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Abstract:
This paper uses data available from the National Opinion Research Center's (NORC) survey on religious attitudes and powerful statistical methods to evaluate the effect of prayer on the attitude of God toward human beings.

kernel estimator, unobserved variables

Abstract:
This paper considers alternative policies for promoting skill formation that are targeted to different stages of the life cycle. We demonstrate the importance of both cognitive and noncognitive skills that are formed early in the life cycle in accounting for racial, ethnic and family background gaps in schooling and other dimensions of socioeconomic success. Most of the gaps in college attendance and delay are determined by early family factors. Children from better families and with high ability earn higher returns to schooling. We find only a limited role for tuition policy or family income supplements in eliminating schooling and college attendance gaps. At most 8% of American youth are credit constrained in the traditional usage of that term. The evidence points to a high return to early interventions and a low return to remedial or compensatory interventions later in the life cycle. Skill and ability beget future skill and ability. At current levels of funding, traditional policies like tuition subsidies, improvements in school quality, job training and tax rebates are unlikely to be effective in closing gaps.

Human Capital, Life Cycle

Abstract:
This paper considers alternative policies for promoting skill formation that are targetted to different stages of the life cycle. We demonstrate the importance of both cognitive and noncognitive skills that are formed early in the life cycle in accounting for racial, ethnic and family background gaps in schooling and other dimensions of socioeconomic success. Most of the gaps in college attendance and delay are determined by early family factors. Children from better families and with high ability earn higher returns to schooling. We find only a limited role for tuition policy or family income supplements in eliminating schooling and college attendance gaps. At most 8% of American youth are credit constrained in the traditional usage of that term. The evidence points to a high return to early interventions and a low return to remedial or compensatory interventions later in the life cycle. Skill and ability beget future skill and ability. At current levels of funding, traditional policies like tuition subsidies, improvements in school quality, job training and tax rebates are unlikely to be effective in closing gaps.

Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Abstract:
This paper considers the interpretation of "Mincer rates of return". We test and reject the Mincer model. It fails to track the time series of true returns. We show how repeated cross section and panel data improves the ability of analysts to estimate the ex ante and ex post marginal rate of returns. Accounting for sequential revelation of information calls into question the validity of the internal rate of return as a tool for policy analysis. The large estimated psychic costs of schooling found in recent work helps to explain why persons do not attend school even though the financial rewards for doing so are high. We present methods for computing distributions of ex post and ex ante returns.

Abstract:
Numerous studies regress log earnings on schooling and report estimated coefficients as "Mincer rates of return". A more recent literature uses instrumental variables. This chapter considers the economic interpretation of these analyses and how the availability of repeated cross section and panel data improves the ability of analysts to estimate the rate of return. We consider under what conditions the Mincer model estimates an ex post rate of return. We test and reject the model on six cross sections of U.S. Census data. We present a general nonparametric approach for estimating marginal internal rates of return that takes into account tuition, income taxes and forms of uncertainty. We also contrast estimates based on a single cross-section of data, using the synthetic cohort approach, with estimates based on repeated cross-sections following actual cohorts. Cohort-based models fitted on repeated cross section data provide more reliable estimates of ex post returns. Accounting for uncertainty affects estimates of rates of return. Accounting for sequential revelation of information calls into question the validity of the internal rate of return as a tool for policy analysis. An alternative approach to computing economic rates of return that accounts for sequential revelation of information is proposed and the evidence is summarized. We distinguish ex ante from ex post returns. New panel data methods for estimating the uncertainty and psychic costs facing agents are reviewed. We report recent evidence that demonstrates that there are large psychic costs of schooling. This helps to explain why persons do not attend school even though the financial rewards for doing so are high. We present methods for computing distributions of returns ex ante and ex post. We review the literature on IV estimation. The link of the estimates to the economics is not strong. The traditional instruments are weak, and this literature has not produced decisive empirical estimates. We exposit new methods that interpret the economic content of different instruments within a unified framework.

rate of return to schooling, internal rate of return, uncertainty, psychic costs, panel data, distribution

Abstract:
The Mincer earnings function is the cornerstone of a large literature in empirical economics. This paper discusses the theoretical foundations of the Mincer model and examines the empirical support for it using data from Decennial Censuses and Current Population surveys. While data from the 1940 and 1950 Censuses provide some support for Mincer's model, data from later decades are inconsistent with it. We examine the importance of relaxing functional form assumptions in estimating internal rates of return to schooling and in accounting for taxes, tuition, nonlinearity in schooling, and nonseparability between schooling and work experience. Inferences about trends in rates of return to high school and college obtained from our more general model differ substantially from inferences drawn from estimates based on a Mincer earnings regression. Important differences also arise between cohort-based and cross-sectional estimates of the rate of return to school. In the recent period of rapid technological change, widely used cross-sectional applications of the Mincer model produce dramatically biased estimates of cohort returns to schooling. We also examine the implications of accounting for uncertainty and agent expectation formation. Even when the static framework of Mincer is maintained, accounting for uncertainty substantially affects rate of return estimates. Considering the sequential resolution of uncertainty over time in a dynamic setting gives rise to option values, which fundamentally changes the analysis of schooling decisions. In the presence of sequential resolution of uncertainty and option values, the internal rate of return - a cornerstone of classical human capital theory - is not a useful guide to policy analysis.

Mincer Model, Earnings Regressions, Returns to Schooling

Abstract:
The Mincer earnings function is the cornerstone of a large literature in empirical economics. This paper discusses the theoretical foundations of the Mincer model and examines the empirical support for it using data from Decennial Censuses and Current Population Surveys. While data from 1940 and 1950 Censuses provide some support for Mincer's model, data from later decades are inconsistent with it. We examine the importance of relaxing functional form assumptions in estimating internal rates of return to schooling and of accounting for taxes, tuition, nonlinearity in schooling, and nonseparability between schooling and work experience. Inferences about trends in rates of return to high school and college obtained from our more general model differ substantially from inferences drawn from estimates based on a Mincer earnings regression. Important differences also arise between cohort-based and cross-sectional estimates of the rate of return to schooling. In the recent period of rapid technological progress, widely used cross-sectional applications of the Mincer model produce dramatically biased estimates of cohort returns to schooling. We also examine the implications of accounting for uncertainty and agent expectation formation. Even when the static framework of Mincer is maintained, accounting for uncertainty substantially affects the return estimates. Considering the sequential resolution of uncertainty over time in a dynamic setting gives rise to option values, which fundamentally changes the analysis of schooling decisions. In the presence of sequential resolution of uncertainty and option values, the internal rate of return - a cornerstone of classical human capital theory - is not a useful guide to policy analysis.

Abstract:
This paper discusses (a) the role of cognitive and noncognitive ability in shaping adult outcomes, (b) the early emergence of differentials in abilities between children of advantaged families and children of disadvantaged families, (c) the role of families in creating these abilities, (d) adverse trends in American families, and (e) the effectiveness of early interventions in offsetting these trends. Practical issues in the design and implementation of early childhood programs are discussed.

Abstract:
This paper discusses (a) the role of cognitive and noncognitive ability in shaping adult outcomes, (b) the early emergence of differentials in abilities between children of advantaged families and children of disadvantaged families, (c) the role of families in creating these abilities, (d) adverse trends in American families, and (e) the effectiveness of early interventions in offsetting these trends. Practical issues in the design and implementation of early childhood programs are discussed.

productivity, high school dropout, ability gaps, family influence, noncognitive skills, early interventions

Abstract:
This paper presents economic models of child development that capture the essence of recent findings from the empirical literature on skill formation. The goal of this essay is to provide a theoretical framework for interpreting the evidence from a vast empirical literature, for guiding the next generation of empirical studies, and for formulating policy. Central to our analysis is the concept that childhood has more than one stage. We formalize the concepts of self-productivity and complementarity of human capital investments and use them to explain the evidence on skill formation. Together, they explain why skill begets skill through a multiplier process. Skill formation is a life cycle process. It starts in the womb and goes on throughout life. Families play a role in this process that is far more important than the role of schools. There are multiple skills and multiple abilities that are important for adult success. Abilities are both inherited and created, and the traditional debate about nature versus nurture is scientifically obsolete. Human capital investment exhibits both self-productivity and complementarity. Skill attainment at one stage of the life cycle raises skill attainment at later stages of the life cycle (self-productivity). Early investment facilitates the productivity of later investment (complementarity). Early investments are not productive if they are not followed up by later investments (another aspect of complementarity). This complementarity explains why there is no equity-efficiency trade-off for early investment. The returns to investing early in the life cycle are high. Remediation of inadequate early investments is difficult and very costly as a consequence of both self-productivity and complementarity.

skill formation, education, government policy, educational finance

Abstract:
This paper presents economic models of child development that capture the essence of recent findings from the empirical literature on skill formation. The goal of this essay is to provide a theoretical framework for interpreting the evidence from a vast empirical literature, for guiding the next generation of empirical studies, and for formulating policy. Central to our analysis is the concept that childhood has more than one stage. We formalize the concepts of self-productivity and complementarity of human capital investments and use them to explain the evidence on skill formation. Together, they explain why skill begets skill through a multiplier process. Skill formation is a life cycle process. It starts in the womb and goes on throughout life. Families play a role in this process that is far more important than the role of schools. There are multiple skills and multiple abilities that are important for adult success. Abilities are both inherited and created, and the traditional debate about nature versus nurture is scientifically obsolete. Human capital investment exhibits both self-productivity and complementarity. Skill attainment at one stage of the life cycle raises skill attainment at later stages of the life cycle (self-productivity). Early investment facilitates the productivity of later investment (complementarity). Early investments are not productive if they are not followed up by later investments (another aspect of complementarity). This complementarity explains why there is no equity-efficiency trade-off for early investment. The returns to investing early in the life cycle are high. Remediation of inadequate early investments is difficult and very costly as a consequence of both self-productivity and complementarity.

Abstract:
This paper presents a productivity argument for investing in disadvantaged young children. For such investment, there is no equity-efficiency tradeoff.

early childhood investment, noncognitive skills, cognitive skills

Abstract:
This paper presents a productivity argument for investing in disadvantaged young children. For such investment, there is no equity-efficiency tradeoff.

Abstract:
Improvements in education and educational quality are widely acknowledged to be major contributors to black economic progress in the Twentieth Century. This paper investigates the sources of improvement in black education in the South in the first half of the century and demonstrates the important roles of social activism, especially NAACP litigation and private philanthropy, in improving the quality and availability of public schooling. Many scholars view education as a rival to social activism in explaining black economic progress, but such a view misses the important role of philanthropic and legal interventions in promoting education.

Abstract:
Making use of restrictions imposed by equilibrium, theoretical progress has been made on the nonparametric and semiparametric estimation and identification of scalar additive hedonic models (Ekeland, Heckman, and Nesheim, 2002) and scalar nonadditive hedonic models (Heckman, Matzkin, and Nesheim, 2002). However, little is known about the practical aspects of estimating such models or of the characteristics of equilibrium in such models. This paper presents computational and analytical results that fill some of these gaps. We simulate and estimate examples of equilibrium in the additive hedonic models and provide evidence on the performance of several estimation techniques. We also simulate examples of equilibria in nonadditive models and provide evidence on the performance of the nonadditive estimation techniques developed in Heckman, Matzkin, and Nesheim (2002).

hedonic models, nonparametric methods, simulation, Monte Carlo, additive models, nonadditive models

Abstract:
This paper investigates four topics. (1) It examines the different roles played by the propensity score (probability of selection) in matching, instrumental variable and control functions methods. (2) It contrasts the roles of exclusion restrictions in matching and selection models. (3) It characterizes the sensitivity of matching to the choice of conditioning variables and demonstrates the greater robustness of control function methods to misspecification of the conditioning variables. (4) It demonstrates the problem of choosing the conditioning variables in matching and the failure of conventional model selection criteria when candidate conditioning variables are not exogenous.

Matching, Control Functions, Instrumental Variables, Discrete Choice, Identification

Abstract:
This paper investigates four topics. (1) It examines the different roles played by the propensity score (probability of selection) in matching, instrumental variable and control functions methods. (2) It contrasts the roles of exclusion restrictions in matching and selection models. (3) It characterizes the sensitivity of matching to the choice of conditioning variables and demonstrates the greater robustness of control function methods to misspecification of the conditioning variables. (4) It demonstrates the problem of choosing the conditioning variables in matching and the failure of conventional model selection criteria when candidate conditioning variables are not exogenous.

Abstract:
This paper develops a model of skill formation that explains a variety of findings established in the child development and child intervention literatures. At its core is a technology that is stage-specific and that features self productivity, dynamic complementarity and skill multipliers. Lessons are drawn for the design of new policies to alleviate the consequences of the accident of birth that is a major source of human inequality.

self productivity, skill multiplier, dynamic complementarity, accident of birth

Abstract:
This paper develops a model of skill formation that explains a variety of findings established in the child development and child intervention literatures. At its core is a technology that is stage-specific and that features self productivity, dynamic complementarity and skill multipliers. Lessons are drawn for the design of new policies to alleviate the consequences of the accident of birth that is a major source of human inequality.

Abstract:
This paper presents the econometric approach to causal modeling. It is motivated by policy problems. New causal parameters are defined and identified to address specific policy problems. Economists embrace a scientific approach to causality and model the preferences and choices of agents to infer subjective (agent) evaluations as well as objective outcomes. Anticipated and realized subjective and objective outcomes are distinguished. Models for simultaneous causality are developed. The paper contrasts the Neyman-Rubin model of causality with the econometric approach.

anticipated vs. realized outcomes, subjective and objective evaluations, Neyman-Rubin model, Roy model, econometrics, causality, counterfactuals, treatment effects

Abstract:
This paper presents the econometric approach to causal modeling. It is motivated by policy problems. New causal parameters are defined and identified to address specific policy problems. Economists embrace a scientific approach to causality and model the preferences and choices of agents to infer subjective (agent) evaluations as well as objective outcomes. Anticipated and realized subjective and objective outcomes are distinguished. Models for simultaneous causality are developed. The paper contrasts the Neyman-Rubin model of causality with the econometric approach.

Abstract:
This paper summarizes our recent research on evaluating the distributional consequences of social programs. This research advances the economic policy evaluation literature beyond estimating assorted mean impacts to estimate distributions of outcomes generated by different policies and determine how those policies shift persons across the distributions of potential outcomes produced by them. Our approach enables analysts to evaluate the distributional effects of social programs without invoking the "Veil of Ignorance" assumption often used in the literature in applied welfare economics. Our methods determine which persons are affected by a given policy, where they come from in the ex-ante outcome distribution and what their gains are. We apply our methods to analyze two proposed policy reforms in American education. These reforms benefit the middle class and not the poor.

Social Programs, Distributional Effects, Policy Evaluation

Abstract:
This paper summarizes our recent research on evaluating the distributional consequences of social programs. This research advances the economic policy evaluation literature beyond estimating assorted mean impacts to estimate distributions of outcomes generated by different policies and determine how those policies shift persons across the distributions of potential outcomes produced by them. Our approach enables analysts to evaluate the distributional effects of social programs without invoking the 'Veil of Ignorance' assumption often used in the literature in applied welfare economics. Our methods determine which persons are affected by a given policy, where they come from in the ex-ante outcome distribution and what their gains are. We apply our methods to analyze two proposed policy reforms in American education. These reforms benefit the middle class and not the poor.

Abstract:
This paper compares the economic questions addressed by instrumental variables estimators with those addressed by structural approaches. We discuss Marschak's Maxim: estimators should be selected on the basis of their ability to answer well-posed economic problems with minimal assumptions. A key identifying assumption that allows structural methods to be more informative than IV can be tested with data and does not have to be imposed.

Abstract:
This paper compares the economic questions addressed by instrumental variables estimators with those addressed by structural approaches. We discuss Marschak's Maxim: estimators should be selected on the basis of their ability to answer well-posed economic problems with minimal assumptions. A key identifying assumption that allows structural methods to be more informative than IV can be tested with data and does not have to be imposed.

instrumental variables, structural approaches, Marschak's Maxim

Abstract:
This paper begins the synthesis of two currently unrelated literatures: the human capital approach to health economics and the economics of cognitive and noncognitive skill formation. A lifecycle investment framework is the foundation for understanding the origins of human inequality and for devising policies to reduce it.

critical periods, sensitive periods, early childhood, Barker hypothesis

Abstract:
This paper begins the synthesis of two currently unrelated literatures: the human capital approach to health economics and the economics of cognitive and noncognitive skill formation. A lifecycle investment framework is the foundation for understanding the origins of human inequality and for devising policies to reduce it.

Abstract:
This paper uses multiple data sources and a unified methodology to estimate the trends and levels of the U.S. high school graduation rate. Correcting for important biases that plague previous calculations, we establish that (a) the true high school graduation rate is substantially lower than the official rate issued by the National Center for Educational Statistics; (b) it has been declining over the past 40 years; (c) majority/minority graduation rate differentials are substantial and have not converged over the past 35 years; (d) the decline in high school graduation rates occurs among native populations and is not solely a consequence of increasing proportions of immigrants and minorities in American society; (e) the decline in high school graduation explains part of the recent slowdown in college attendance; and (f) the pattern of the decline of high school graduation rates by gender helps to explain the recent increase in male-female college attendance gaps.

high school dropout rate, high school graduation rates, educational attainment

Abstract:
This paper uses multiple data sources and a unified methodology to estimate the trends and levels of the U.S. high school graduation rate. Correcting for important biases that plague previous calculations, we establish that (a) the true high school graduation rate is substantially lower than the official rate issued by the National Center for Educational Statistics; (b) it has been declining over the past 40 years; (c) majority/minority graduation rate differentials are substantial and have not converged over the past 35 years; (d) the decline in high school graduation rates occurs among native populations and is not solely a consequence of increasing proportions of immigrants and minorities in American society; (e) the decline in high school graduation explains part of the recent slowdown in college attendance; and (f) the pattern of the decline of high school graduation rates by gender helps to explain the recent increase in male-female college attendance gaps.

Abstract:
This paper uses Chinese micro data and new semi-parametric methods to estimate the current return to college education allowing for heterogeneous returns and for self-selection into schooling based on them. OLS and IV methods do not properly account for this sorting. Our estimates suggest that, for a randomly selected young person from an urban area, college attendance leads to a 43% increase in lifetime earnings (nearly 11% annually) in 2000, compared with just 36% (nearly 9% annually) for those who do not attend. Our evidence suggests that the return to education has increased substantially in China since the early 1990s.

Abstract:
This paper uses newly available Chinese micro data to estimate the return to college education for late 20th century China when allowing for heterogeneous returns among individuals selecting into schooling based on these differences. We use recently developed semiparametric methods to identify the parameters of interest. We demonstrate that heterogeneity among people in returns to schooling is substantial. People sort into schooling on the basis of the principle of comparative advantage, which we document to be an empirically important phenomenon in modern Chinese labor markets. Standard least squares or instrumental variable methods do not properly account for this sorting. Using new methods that do, we estimate the effect on earnings of sending a randomly selected person to college is a 43% increase in lifetime earnings (nearly 11% annually) in 2000 for young people in urban areas of six provinces of China. The effect of college on those who go is 13%. Our evidence, and simple least squares evidence, suggests that after 20-plus years of economic reform with market orientation, the return to education has increased substantially in China, compared to the returns measured in the 1980's and the early 1990's.

education, returns to education

Abstract:
This paper uses newly available Chinese micro data to estimate the return to college education for late 20th century China when allowing for heterogeneous returns among individuals selecting into schooling based on these differences. We use recently developed semiparametric methods to identify the parameters of interest. We demonstrate that heterogeneity among people in returns to schooling is substantial. People sort into schooling on the basis of the principle of comparative advantage, which we document to be an empirically important phenomenon in modern Chinese labor markets. Standard least squares or instrumental variable methods do not properly account for this sorting. Using new methods that do, we estimate the effect on earnings of sending a randomly selected person to college is a 43% increase in lifetime earnings (nearly 11% annually) in 2000 for young people in urban areas of six provinces of China. The effect of college on those who go is 13%. Our evidence, and simple least squares evidence, suggests that after 20-plus years of economic reform with market orientation, the return to education has increased substantially in China, compared to the returns measured in the 1980's and the early 1990's.

Abstract:
This paper considers the identification and estimation of hedonic models. We establish that in an additive version of the hedonic model, technology and preferences are generically nonparametrically identified from data on demand and supply in a single hedonic market. The empirical literature that claims that hedonic models estimated on data from a single market are fundamentally underidentified is based on arbitrary linearizations that do not use all the information in the model. The exact economic model that justifies linear approximations is unappealing. Nonlinearities are generic features of equilibrium in hedonic models and a fundamental and economically motivated source of identification.

Abstract:
This paper considers the identification and estimation of hedonic models. We establish that in an additive version of the hedonic model, technology and preferences are generically identified up to affine transformations from data on demand and supply in a single hedonic market. For a very general parametric structure preferences and technology are fully identified. This is true under a strong assumption of statistical independence of the error term. It is also true under the weaker assumption of mean independence of the error term. Much of the confusion in the empircial literature that claims that hedonic models estimated on data from a single market are fundamentally underidentified is based on linearizations that do not use all of the information in the model. The exact economic model that justifies widely used linear approximations has strange properties so the approximation is doubly poor. A semiparametric estimation method is proposed that is valid when a statistical independence assumption is valid. Alternatively, under the weaker condition of mean independence instrumental variables estimators can be applied to identify technology and preference parameters from a single market. They are justified by nonlinearities that are generic features of equilibrium in hedonic models.

additive hedonic models, semiparametric estimation

Abstract:
This paper considers the identification and estimation of hedonic models. We establish that in an additive version of the hedonic model, technology and preferences are generically identified up to affine transformations from data on demand and supply in a single hedonic market. For a very general parametric structure, preferences and technology are fully identified. This is true under a strong assumption of statistical independence of the error term. It is also true under the weaker assumption of mean independence of the error term. Much of the confusion in the empirical literature that claims that hedonic models estimated on data from a single market are fundamentally underidentified is based on linearizations that do not use all of the information in the model. The exact economic model that justifies widely used linear approximations has strange properties so the approximation is doubly poor. A semiparametric estimation method is proposed that is valid when a statistical independence assumption is valid. Alternatively, under the weaker condition of mean independence instrumental variables estimators can be applied to identify technology and preference parameters from a single market. They are justified by nonlinearities that are generic features of equilibrium in hedonic models.

Abstract:
This paper examines the performance of the JTPA performance system, a widely emulated model for inducing efficiency in government organizations. We present a model of how performance incentives may distort bureaucratic decisions. We define cream skimming within the model. Two major empirical findings are (a) that the short run measures used to monitor performance are weakly, and sometimes perversely, related to long run impacts and (b) that the efficiency gains or losses from cream skimming are small. We find evidence that centers respond to performance standards.

Performance Standards, Reinventing Government, Evaluation, JTPA

Abstract:
This paper examines the performance of the JTPA performance system, a widely emulated model for inducing efficiency in government organizations. We present a model of how performance incentives may distort bureaucratic decisions. We define cream skimming within the model. Two major empirical findings are (a) that the short run measures used to monitor performance are weakly, and sometimes perversely, related to long run impacts and (b) that the efficiency gains or losses from cream skimming are small. We find evidence that centers respond to performance standards.

Abstract:
This paper explores the interface between personality psychology and economics. We examine the predictive power of personality and the stability of personality traits over the life cycle. We develop simple analytical frameworks for interpreting the evidence in personality psychology and suggest promising avenues for future research.

personality traits, lifecycle effects

Abstract:
This paper examines the properties of instrumental variables (IV) applied to models with essential heterogeneity, that is, models where responses to interventions are heterogeneous and agents adopt treatments (participate in programs) with at least partial knowledge of their idiosyncratic response. We analyze two-outcome and multiple-outcome models including ordered and unordered choice models. We allow for transition-specific and general instruments. We generalize previous analyses by developing weights for treatment effects for general instruments. We develop a simple test for the presence of essential heterogeneity. We note the asymmetry of the model of essential heterogeneity: outcomes of choices are heterogeneous in a general way; choices are not. When both choices and outcomes are permitted to be symmetrically heterogeneous, the method of IV breaks down for estimating treatment parameters.

unobserved heterogeneity, instrumental variables, treatment parameters, policy evaluation

Abstract:
This paper examines the properties of instrumental variables (IV) applied to models with essential heterogeneity, that is, models where responses to interventions are heterogeneous and agents adopt treatments (participate in programs) with at least partial knowledge of their idiosyncratic response. We analyze two-outcome and multiple-outcome models including ordered and unordered choice models. We allow for transition-specific and general instruments. We generalize previous analyses by developing weights for treatment effects for general instruments. We develop a simple test for the presence of essential heterogeneity. We note the asymmetry of the model of essential heterogeneity: outcomes of choices are heterogeneous in a general way; choices are not. When both choices and outcomes are permitted to be symmetrically heterogeneous, the method of IV breaks down for estimating treatment parameters.

Abstract:
This paper develops and applies a method for decomposing cross section variability of earnings into components that are forecastable at the time students decide to go to college (heterogeneity) and components that are unforecastable. About 60% of variability in returns to schooling is forecastable. This has important implications for using measured variability to price risk and predict college attendance.

Abstract:
This paper develops and applies a method for decomposing cross section variability of earnings into components that are forecastable at the time students decide to go to college (heterogeneity) and components that are unforecastable. About 60% of variability in returns to schooling is forecastable. This has important implications for using measured variability to price risk and predict college attendance.

uncertainty, lifecycle earnings, schooling, heterogeneity, counterfactuals

Abstract:
A growing proportion of the U.S. workforce will have been raised in disadvantaged environments that are associated with relatively high proportions of individuals with diminished cognitive and social skills. A cross-disciplinary examination of research in economics, developmental psychology, and neurobiology reveals a striking convergence on a set of common principles that account for the potent effects of early environment on the capacity for human skill development. Central to these principles are the findings that early experiences have a uniquely powerful influence on the development of cognitive and social skills, as well as on brain architecture and neurochemistry; that both skill development and brain maturation are hierarchical processes in which higher level functions depend on, and build on, lower level functions; and that the capacity for change in the foundations of human skill development and neural circuitry is highest earlier in life and decreases over time. These findings lead to the conclusion that the most efficient strategy for strengthening the future workforce, both economically and neurobiologically, and for improving its quality of life is to invest in the environments of disadvantaged children during the early childhood years.

child development, early experience, economic productivity, critical and

Abstract:
A growing proportion of the U.S. workforce will have been raised in disadvantaged environments that are associated with relatively high proportions of individuals with diminished cognitive and social skills. A cross-disciplinary examination of research in economics, developmental psychology, and neurobiology reveals a striking convergence on a set of common principles that account for the potent effects of early environment on the capacity for human skill development. Central to these principles are the findings that early experiences have a uniquely powerful influence on the development of cognitive and social skills, as well as on brain architecture and neurochemistry; that both skill development and brain maturation are hierarchical processes in which higher level functions depend on, and build on, lower level functions; and that the capacity for change in the foundations of human skill development and neural circuitry is highest earlier in life and decreases over time. These findings lead to the conclusion that the most efficient strategy for strengthening the future workforce, both economically and neurobiologically, and for improving its quality of life is to invest in the environments of disadvantaged children during the early childhood years.

Abstract:
This paper considers semiparametric identification of structural dynamic discrete choice models and models for dynamic treatment effects. Time to treatment and counterfactual outcomes associated with treatment times are jointly analyzed. We examine the implicit assumptions of the dynamic treatment model using the structural model as a benchmark. For the structural model we show the gains from using cross equation restrictions connecting choices to associated measurements and outcomes. In the dynamic discrete choice model, we identify both subjective and objective outcomes, distinguishing ex post and ex ante outcomes. We show how to identify agent information sets.

Abstract:
This paper considers semiparametric identification of structural dynamic discrete choice models and models for dynamic treatment effects. Time to treatment and counterfactual outcomes associated with treatment times are jointly analyzed. We examine the implicit assumptions of the dynamic treatment model using the structural model as a benchmark. For the structural model we show the gains from using cross equation restrictions connecting choices to associated measurements and outcomes. In the dynamic discrete choice model, we identify both subjective and objective outcomes, distinguishing ex post and ex ante outcomes. We show how to identify agent information sets.

dynamic treatment effects, dynamic discrete choice, semiparametric identification

Abstract:
We investigate the relative significance of differences in cognitive skills and discrimination in explaining racial/ethnic wage gaps. We show that cognitive test scores taken prior to entering the labor market are influenced by schooling. Adjusting the scores for racial/ethnic differences in education at the time the test is taken reduces their role in accounting for the wage gaps. We also consider evidence on parental and child expectations about education and on stereotype-threat effects. We find both factors to be implausible alternative explanations for the gaps we observe. We argue that policies need to address the sources of early skill gaps and to seek to influence the more malleable behavioral abilities in addition to their cognitive counterparts. Such policies are far more likely to be effective in promoting racial and ethnic equality for most groups than are additional civil rights and affirmative action policies targeted at the workplace.

ability, test scores, gaps, education

Abstract:
This paper examines minority-white wage gaps. Neal and Johnson (1996) show that controlling for ability measured in the teenage years eliminates young adult wage gaps for all groups except for black males, for whom they eliminate 70% of the gap. Their study has been faulted because minority children and their parents may have pessimistic expectations about receiving fair rewards for their skills and so they may invest less in skill formation. If this is the case, discrimination may still affect wages, albeit indirectly, though it would appear that any racial differences in wages are due to differences in acquired traits. We find that gaps in ability across racial and ethnic groups open up at very early ages, long before child expectations are likely to become established. These gaps widen with age and schooling for Blacks, but not for Hispanics which indicates that poor schools and neighborhoods cannot be the principal factors affecting the slow black test score growth rate. Test scores depend on schooling attained at the time of the test. Adjusting for racial and ethnic differences in schooling attainment at the age the test is taken reduces the power of measured ability to shrink wage gaps for blacks, but not for other minorities. The evidence from expectations data are mixed. Although all groups are quite optimistic about future schooling outcomes, minority parents and children have more pessimistic expectations about child schooling relative to white children and their parents when their children are young. At later ages, expectations are more uniform across racial and ethnic groups. However, we also present some evidence that expectations data are unreliable and ambiguous. We also document the presence of disparities in noncognitive traits across racial and ethnic groups. These characteristics have been shown elsewhere to be important for explaining the labor market outcomes of adults. This evidence points to the importance of early (preschool) family factors and environments in explaining both cognitive and noncognitive ability differentials by ethnicity and race. Policies that foster both types of ability are far more likely to be effective in promoting racial and ethnic equality for most groups than are additional civil rights and affirmative action policies targeted at the workplace.

Abstract:
This paper uses factor models to identify and estimate distributions of counterfactuals. We extend LISREL frameworks to a dynamic treatment effect setting, extending matching to account for unobserved conditioning variables. Using these models, we can identify all pairwise and joint treatment effects. We apply these methods to a model of schooling and determine the intrinsic uncertainty facing agents at the time they make their decisions about enrollment in school. Reducing uncertainty in returns raises college enrollment. We go beyond the "Veil of Ignorance" in evaluating educational policies and determine who benefits and loses from commonly proposed educational reforms.

Policy Evaluation, Returns to Schooling, Factor Models, Counterfactual Distributions

Abstract:
This paper develops two methods for estimating the effect of schooling on achievement test scores that control for the endogeneity of schooling by postulating that both schooling and test scores are generated by a common unobserved latent ability. These methods are applied to data on schooling and test scores. Estimates from the two methods are in close agreement. We find that the effects of schooling on test scores are roughly linear across schooling levels. The effects of schooling on measured test scores are slightly larger for lower latent ability levels. We find that schooling increases the AFQT score on average between 2 and 4 percentage points, roughly twice as large as the effect claimed by Herrnstein and Murray (1994) but in agreement with estimates produced by Neal and Johnson (1996) and Winship and Korenman (1997). We extend the previous literature by estimating the impact of schooling on measured test scores at various quantiles of the latent ability distribution.

Education, Ability, Latent Variables, Selection, MCMC

Abstract:
This paper develops two methods for estimating the effect of schooling on achievement test scores that control for the endogeneity of schooling by postulating that both schooling and test scores are generated by a common unobserved latent ability. These methods are applied to data on schooling and test scores. Estimates from the two methods are in close agreement. We find that the effects of schooling on test scores are roughly linear across schooling levels. The effects of schooling on measured test scores are slightly larger for lower latent ability levels. We find that schooling increases the AFQT score on average between 2 and 4 percentage points, roughly twice as large as the effect claimed by Herrnstein and Murray (1994) but in agreement with estimates produced by Neal and Johnson (1996) and Winship and Korenman (1997). We extend the previous literature by estimating the impact of schooling on measured test scores at various quantiles of the latent ability distribution.

Abstract:
This paper presents a new framework for analyzing inequality that moves beyond the anonymity postulate. We estimate the determinants of sectoral choice and the joint distributions of outcomes across sectors. We determine which components of realized earnings variability are due to uncertainty and which components are due to components of human diversity that are forecastable by agents. Using our tools, we can determine how policies shift persons across sectors and outcome distributions across sectors.

inequality, anonymity postulate, uncertainty, policy evaluation

Abstract:
This paper presents a new framework for analyzing inequality that moves beyond the anonymity postulate. We estimate the determinants of sectoral choice and the joint distributions of outcomes across sectors. We determine which components of realized earnings variability are due to uncertainty and which components are due to components of human diversity that are forcastable by agents. Using our tools, we can determine how policies shift persons across sectors and outcome distributions across sectors.

Abstract:
In this article, I summarize Griliches' contributions to economics and to applied econometrics.

social rate of return, growth, productivity improvement

Abstract:
This paper summarizes the major research contributions of Zvi Griliches.

Abstract:
This paper demonstrates gender differences in risk aversion and ambiguity aversion. It also contributes to a growing literature relating economic preference parameters to psychological measures by asking whether variations in preference parameters among persons, and in particular across genders, can be accounted for by differences in personality traits and traits of cognition. Women are more risk averse than men. Over an initial range, women require no further compensation for the introduction of ambiguity but men do. At greater levels of ambiguity, women have the same marginal distaste for increased ambiguity as men. Psychological variables account for some of the interpersonal variation in risk aversion. They explain none of the differences in ambiguity.

gender, risk aversion, ambiguity aversion

Abstract:
This paper demonstrates gender differences in risk aversion and ambiguity aversion. It also contributes to a growing literature relating economic preference parameters to psychological measures by asking whether variations in preference parameters among persons, and in particular across genders, can be accounted for by differences in personality traits and traits of cognition. Women are more risk averse than men. Over an initial range, women require no further compensation for the introduction of ambiguity but men do. At greater levels of ambiguity, women have the same marginal distaste for increased ambiguity as men. Psychological variables account for some of the interpersonal variation in risk aversion. They explain none of the differences in ambiguity.

Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Abstract:
This paper decomposes the participation process of a prototypical program into eligibility, awareness, application, acceptance and enrollment. With this decomposition, we determine the sources of unequal participation for different groups, and demonstrate that variables often have very different effects at different stages in the participation process. Our analysis shows that personal choices substantially affect participation and that awareness of program eligibility is a major source of variation in participation.

Abstract:
This paper decomposes the participation process of a prototypical program into eligibility, awareness, application, acceptance and enrollment. With this decomposition, we determine the sources of unequal participation for different groups, and demonstrate that variables often have very different effects at different stages in the participation process. Our analysis shows that personal choices substantially affect participation and that awareness of program eligibility is a major source of variation in participation.

Social Program Participation, Job Training, Performance Standards, Cream Skimming, Job Training Partnership Act (JTPA)

Abstract:
This paper examines the family income-college enrollment relationship and the evidence on credit constraints in post-secondary schooling. We distinguish short-run liquidity constraints from the long-term factors that promote cognitive and noncognitive ability. Long-run factors crystallized in ability are the major determinants of the family income-schooling relationship, although there is some evidence that up to 8% of the U.S. population is credit constrained in a short-run sense. Evidence that IV estimates of the returns to schooling exceed OLS estimates is sometimes claimed to support the existence of substantial credit constraints. This argument is critically examined.

Human Capital, Return to Education, Credit Constraints

Abstract:
This paper examines the family income - college enrollment relationship and the evidence on credit constraints in post-secondary schooling. We distinguish short-run liquidity constraints from the long-term factors that promote cognitive and noncognitive ability. Long-run factors crystallized in ability are the major determinants of the family income - schooling relationship, although there is some evidence that up to 8% of the U.S. population is credit constrained in a short-run sense. Evidence that IV estimates of the returns to schooling exceed OLS estimates is sometimes claimed to support the existence of substantial credit constraints. This argument is critically examined.

Abstract:
Recent research on the economics of human development deepens understanding of the origins of inequality and excellence. It draws on and contributes to personality psychology and the psychology of human development. Inequalities in family environments and investments in children are substantial. They causally affect the development of capabilities. Both cognitive and noncognitive capabilities determine success in life but to varying degrees for different outcomes. An empirically determined technology of capability formation reveals that capabilities are self-productive and cross-fertilizing and can be enhanced by investment. Investments in capabilities are relatively more productive at some stages of a child's life cycle than others. Optimal child investment strategies differ depending on target outcomes of interest and on the nature of adversity in a child's early years. For some configurations of early disadvantage and for some desired outcomes, it is efficient to invest relatively more in the later years of childhood than in the early years.

inequality, capabilities, noncognitive traits, human development, technology of capability formation, policy targeting

Abstract:
Recent research on the economics of human development deepens understanding of the origins of inequality and excellence. It draws on and contributes to personality psychology and the psychology of human development. Inequalities in family environments and investments in children are substantial. They causally affect the development of capabilities. Both cognitive and noncognitive capabilities determine success in life but to varying degrees for different outcomes. An empirically determined technology of capability formation reveals that capabilities are self-productive and cross-fertilizing and can be enhanced by investment. Investments in capabilities are relatively more productive at some stages of a child's life cycle than others. Optimal child investment strategies differ depending on target outcomes of interest and on the nature of adversity in a child's early years. For some configurations of early disadvantage and for some desired outcomes, it is efficient to invest relatively more in the later years of childhood than in the early years.

Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.

Abstract:
The internal rate of return to schooling is a fundamental economic parameter that is often used to assess whether expenditure on education should be increased or decreased. This paper considers alternative approaches to estimating marginal internal rates of return for different schooling levels. We implement a general nonparametric approach to estimate marginal internal rates of return that take into account tuition costs, income taxes and nonlinearities in the earnings-schooling-experience relationship. The returns obtained by the more general method differ substantially from Mincer returns in levels and in their evolution over time. They indicate relatively larger returns to graduating from high school than from graduating from college, although both have been increasing over time.

schooling, marginal internal rate of return, nonparametric estimation

Abstract:
The internal rate of return to schooling is a fundamental economic parameter that is often used to assess whether expenditure on education should be increased or decreased. This paper considers alternative approaches to estimating marginal internal rates of return for different schooling levels. We implement a general nonparametric approach to estimate marginal internal rates of return that take into account tuition costs, income taxes and nonlinearities in the earnings-schooling-experience relationship. The returns obtained by the more general method differ substantially from Mincer returns in levels and in their evolution over time. They indicate relatively larger returns to graduating from high school than from graduating from college, although both have been increasing over time.

Abstract:
A large empirical literature documents a rise in wage inequality in the American economy. It is silent on whether the increase in inequality is due to greater heterogeneity in the components of earnings that are predictable by agents or whether it is due to greater uncertainty faced by agents. Applying the methodology of Cunha, Heckman, and Navarro (2005) to data on agents making schooling decisions in different economic environments, we join choice data with earnings data to estimate the fraction of future earnings that is forecastable and how this fraction has changed over time. We find that both predictable and unpredictable components of earnings have increased in recent years. The increase in uncertainty is substantially greater for unskilled workers. For less skilled workers, roughly 60% of the increase in wage variability is due to uncertainty. For more skilled workers, only 8% of the increase in wage variability is due to uncertainty. Roughly 26% of the increase in the variance of returns to schooling is due to increased uncertainty. Using conventional measures of income inequality masks the contribution of rising uncertainty to the rise in the inequality of earnings for less educated groups.

wage inequality, uncertainty, sorting, inequality accounting

Abstract:
This paper argues that skill formation is a life-cycle process and develops the implications of this insight for Scottish social policy. Families are major producers of skills, and a successful policy needs to promote effective families and to supplement failing ones. We present evidence that early disadvantages produce severe later disadvantages that are hard to remedy. We also show that cognitive ability is not the only determinant of education, labor market outcomes and pathological behavior like crime. Abilities differ in their malleability over the life-cycle, with noncognitive skills being more malleable at later ages. This has important implications for the design of policy. The gaps in skills and abilities open up early, and schooling merely widens them. Additional university tuition subsidies or improvements in school quality are not warranted by Scottish evidence. Company-sponsored job training yields a higher return for the most able and so this form of investment will exacerbate the gaps it is intended to close. For the same reason, public job training is not likely to help adult workers whose skills are rendered obsolete by skill-biased technological change. Targeted early interventions, however, have proven to be very effective in compensating for the effect of neglect.

Scotland, education, training, family, policy

Abstract:
In this paper, I present a simple characterization of the sample selection bias problem that is also applicable to the conceptually distinct econometric problems that arise from truncated samples and from models with limited dependent variables. The problem of sample selection bias is fit within the conventional specification error framework of Griliches and Theil. A simple estimator is discussed that enables analysts to utilize ordinary regression methods to estimate models free of selection bias. The techniques discussed here are applied to re-estimate and test a model of female labor supply developed by the author. (1974). This paper is in three parts. In the first section, selection bias is presented within the specification error framework. In this section, general distributional assumptions are maintained. In section two, specific results are presented for the case of normal regression disturbances. Simple estimators are proposed and discussed. In the third section, empirical results are presented.

Abstract:
This paper considers the formulation and estimation of simultaneous equation models with both discrete and continuous endogenous variables. The statistical model proposed here is sufficiently rich to encompass the classical simultaneous equation model for continuous endogenous variables and more recent models for purely discrete endogenous variables as special cases of a more general model.

Abstract:
This paper discusses evidence on human capital investment in China. Policies through the mid 1990s favor physical investment over schooling.

Abstract:
This paper considers the sources of skill formation in a modern economy and emphasizes the importance of both cognitive and noncognitive skills in producing economic and social success and the importance of both formal academic institutions and families and firms as sources of learning. Skill formation is a dynamic process with strong synergistic components. Skill begets skill. Early investment promotes later investment. Noncognitive skills and motivation are important determinants of success and these can be improved more successfully and at later ages than basic cognitive skills. Methods currently used to evaluate educational interventions ignore these noncogntive skills and therefore substantially understate the benefits of early intervention programs and mentoring and teenage motivation programs. At current levels of investment, American society underinvests in the very young and overinvests in mature adults with low skills.

Abstract:
This paper considers the sources of skill formation in a modern economy and emphasizes the importance of both cognitive and noncognitive skills in producing economic and social success and the importance of both formal academic institutions and families and firms as sources of learning. Skill formation is a dynamic process with strong synergistic components. Skill begets skill. Early investment promotes later investment. Noncognitive skills and motivation are important determinants of success and these can be improved more successfully and at later ages than basic cognitive skills. Methods currently used to evaluate educational interventions ignore these noncogntive skills and therefore substantially understate the benefits of early intervention programs and mentoring and teenage motivation programs. At current levels of investment, American society underinvests in the very young and overinvests in mature adults with low skills.

Abstract:
This paper uses factor models to identify and estimate distributions of counterfactuals. We extend LISREL frameworks to a dynamic treatment effect setting, extending matching to account for unobserved conditioning variables. Using these models, we can identify all pairwise and joint treatment effects. We apply these methods to a model of schooling and determine the intrinsic uncertainty facing agents at the time they make their decisions about enrollment in school. Reducing uncertainty in returns raises college enrollment. We go beyond the 'Veil of Ignorance' in evaluating educational policies and determine who benefits and who loses from commonly proposed educational reforms.

Abstract:
This paper documents the high level of job security protection in Latin American labor markets and analyzes its impact on employment. We show that job security policies have substantial impact on the level and the distribution of employment in Latin America. They reduce employment and promote inequality. The institutional organization of the labor market affects both employment and inequality.

Abstract:
This paper estimates a dynamic model of schooling attainment to investigate the sources of discrepancy by race and ethnicity in college attendance. When the returns to college education rose, college enrollment of whites responded much more quickly than that of minorities. Parental income is a strong predictor of this response. However, using NLSY data, we find that it is the long-run factors associated with parental background and income and not short-term credit constraints facing college students that account for the differential response by race and ethnicity to the new labor market for skilled labor. Policies aimed at improving these long-term factors are far more likely to be successful in eliminating college attendance differentials than are short-term tuition reduction policies.

Abstract:
This paper discusses recent advances in our understanding of differences in human abilities and skills, their sources, and their evolution over the lifecycle.

Abstract:
No abstract is available for this paper.

Abstract:
This paper analyzes the causes and consequences of the growing proportion of high-school-certified persons who achieve that status by exam certification rather than through high school graduation. Exam-certified high school equivalents are
statistically indistinguishable from high school dropouts. Both dropouts and exam-certified equivalents have comparably poor wages, earnings, hours of work, unemployment experiences and job tenure. This is so whether or not ability measures are used to control for differences. Whatever differences are found among exam-certified equivalents, high school dropouts and high school graduates are accounted for by their years of schooling completed. There is no cheap substitute for schooling. The only payoff to exam certification arises from its value in opening post-secondary schooling and training opportunities. However, exam-certified equivalents receive lower returns to most forms of post-secondary education and training.

We also discuss the political economy of the recent rapid growth of exam certification. There has been growth in direct government subsidies to adult basic education proggrams that feature exam certification as an output. In addition, there has been growth in government subsidies to post-secondary schooling programs that require certification in order to qualify for benefits. These sources account for the rapid growth in the use of exam certification in the face of the low economic returns to it.

Abstract:
This paper develops and applies semiparametric econometric methods to estimate the form of selection bias that arises from using nonexperimental comparison groups to evaluate social programs and to test the identifying assumptions that justify three widely-used classes of estimators and our extensions of them: (a) the method of matching; (b) the classical econometric selection model which represents the bias solely as a function of the probability of participation; and (c) the method of difference-in-differences. Using data from an experiment on a prototypical social program combined with unusually rich data from a nonexperimental comparison group, we reject the assumptions justifying matching and our extensions of that method but find evidence in support of the index-sufficient selection bias model and the assumptions that justify application of a conditional semiparametric version of the method of difference-in-difference. Fa comparable people and to appropriately weight participants and nonparticipants a sources of selection bias as conveniently measured. We present a rigorous defin bias and find that in our data it is a small component of conventially meausred it is still substantial when compared with experimentally-estimated program impa matching participants to comparison group members in the same labor market, givi same questionnaire, and making sure they have comparable characteristics substan the performance of any econometric program evaluation estimator. We show how t analysis to estimate the impact of treatment on the treated using ordinary observational data.