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Abstract:
Estimates of the effect of education on GDP (the social return to education) have been hard to reconcile with micro-evidence on the private return. We present a simple explanation that combines two ideas: Imperfect substitution between worker types and endogenous skill-biased technological progress. When types of workers are imperfect substitutes, the supply of human capital is negatively related to its return, and a higher education level compresses wage differentials. We use cross-country panel data on income inequality to estimate the private return and GDP data to estimate the social return. The results show that the private return falls by 1.5 percentage points when the average education level increases by a year, which is consistent with Katz and Murphy's (1992) estimate of the elasticity of substitution between worker types. We find no evidence for dynamics in the private return, and certainly not for a reversal of the negative effect as described in Acemoglu (2002). The short-run social return equals the private return, but the long-run return is two times higher, providing evidence in favour of endogenous technological progress. The rise in education is the major cause of productivity growth over the sample period 1960-90.

Education, inequality, growth

Abstract:
When types of workers are imperfect substitutes, the Mincerian rate of return to human capital is negatively related to the supply of human capital. We work out a simple model for the joint evolution of output and wage dispersion. We estimate this model using cross-country panel data on GDP and Gini coefficients. The results are broadly consistent with our hypothesis of diminishing returns to education. The implied elasticity of substitution fits Katz and Murphy's (1992) estimate. A one year increase in the stock of human capital reduces the rate of return by about 2 percent. The combination of imperfect substitution and skill biased technological change closes the gap between the Mincer equation and GDP growth regressions almost completely.

Abstract:
We use CEX repeated cross-section data on consumption and income, to evaluate the nature of increased income inequality in the 1980s and 90s. We decompose unexpected changes in family income into transitory and permanent, and idiosyncratic and aggregate components, and estimate the contribution of each component to total inequality. The model we use is a linearized incomplete markets model, enriched to incorporate risk-sharing while maintaining tractability. Our estimates suggest that taking risk sharing into account is important for the model fit; that the increase in inequality in the 1980s was mainly permanent; and that inequality is driven almost entirely by idiosyncratic income risk. In addition we find no evidence for cyclical behavior of consumption risk, casting doubt on Constantinides and Duffie's (1995) explanation for the equity premium puzzle.

consumption, inequality, risk, incomplete markets, business cycle

Abstract:
Shimer (2005) and Hall (2005) have documented the failure of standard labor market search models to match business cycle fluctuations in employment and unemployment. They argue that it is likely that wages are not adjusted as regularly as suggested by the model, which would explain why employment is more volatile than the model predicts. We explore whether this explanation is consistent with the data. The main insight is that the relevant wage data for the search model are not aggregate wages, but wages of newly hired workers. Our results show that wages for those workers are much more volatile than aggregate wages and respond one-for-one to changes in labor productivity. Thus, we find no evidence for wage rigidity.

Wage Rigidity, Search and Matching Model, Business Cycle

Abstract:
Was the increase in income inequality in the US due to permanent shocks or merely to an increase in the variance of transitory shocks? The implications for consumption and welfare depend crucially on the answer to this question. We use CEX repeated cross-section data on consumption and income to decompose idiosyncratic changes in income into predictable life-cycle changes, transitory and permanent shocks and estimate the contribution of each to total inequality. Our model fits the joint evolution of consumption and income inequality well and delivers two main results. First, we find that permanent changes in income explain all of the increase in inequality in the 1980s and 90s. Second, we reconcile this finding with the fact that consumption inequality did not increase much over this period. Our results support the view that many permanent changes in income are predictable for consumers, even if they look unpredictable to the econometrician, consistent with models of heterogeneous income profiles.

consumption, inequality, risk, heterogeneous income profiles

Abstract:
Over the past two decades, technological progress has been biased towards making skilled labor more productive. The evidence for this finding is based on the persistent parallel increase in the skill premium and the supply of skilled workers. What are the implications of skill-biased technological change for the business cycle? To answer this question, we use the CPS outgoing rotation groups to construct quarterly series for the price and quantity of skill. The unconditional correlation of the skill premium with the cycle is zero. However, using a structural VAR with long run restrictions, we find that technology shocks substantially increase the premium. Investment-specific technology shocks are not skill-biased and our findings suggest that capital and skill are (mildly) substitutable in aggregate production.

Skill-biased technology, skill premium, VAR, long-run restrictions, capital-skill complementarity, business cycle

Abstract:
In this paper I present a model in which production requires two types of labor inputs: regular productive tasks and organizational capital, which is accumulated by workers performing organizational tasks. By allocating more workers from organizational to productive tasks, firms can temporarily increase production without hiring. The availability of this intensive margin of labor adjustment, in combination with adjustment costs along the extensive margin (search frictions, firing costs, training costs), makes it optimal to delay employment adjustments. Simulations indicate that this mechanism is quantitatively important even if only a small fraction of workers perform organizational tasks, and explains why the hiring rate is persistent and why employment is slow to recover after the end of a recession.

business cycles, labor market, organizational capital, jobless recoveries

Abstract:
Standard macroeconomic models underpredict the volatility of unemployment fluctuations. A common solution is to assume wages are rigid. We explore whether this explanation is consistent with the data. We show that the wage of newly hired workers, unlike the aggregate wage, is volatile and responds one-to-one to changes in labor productivity. In order to replicate these findings in a search model, it must be that wages are rigid in ongoing jobs but flexible at the start of new jobs. This form of wage rigidity does not affect job creation and thus cannot explain the unemployment volatility puzzle.

wage rigidity, search and matching model, business cycle

Abstract:
Was the increase in income inequality in the US due to permanent shocks or merely to an increase in the variance of transitory shocks? The implications for consumption and welfare depend crucially on the answer to this question. We use CEX repeated cross-section data on consumption and income to decompose idiosyncratic changes in income into predictable life-cycle changes, transitory and permanent shocks and estimate the contribution of each to total inequality. Our model fits the joint evolution of consumption and income inequality well and delivers two main results. First, we find that permanent changes in income explain all of the increase in inequality in the 1980s and 90s. Second, we reconcile this finding with the fact that consumption inequality did not increase much over this period. Our results support the view that many permanent changes in income are predictable for consumers, even if they look unpredictable to the econometrician, consistent with models of heterogeneous income profiles.

Consumption, inequality, risk, incomplete markets, heterogeneous income profiles

Abstract:
Over the past two decades, technological progress has been biased towards making skilled labor more productive. What does skill-biased technological change imply for business cycles? To answer this question, we construct a quarterly series for the skill premium from the CPS and use it to identify skill-biased technology shocks in a VAR with long run restrictions. We find that hours worked fall in response to skill-biased, but not in response to skill-neutral improvements in technology. Skill-biased technology shocks are associated with increases in the relative price of investment, indicating that capital and skill are substitutes in aggregate production.

skill-biased technology, skill premium, VAR, long-run restrictions, capital-skill complementarity, business cycle

Abstract:
Was the increase in income inequality in the US due to permanent shocks or merely to an increase in the variance of transitory shocks? The implications for consumption and welfare depend crucially on the answer to this question. We use CEX repeated cross-section data on consumption and income to decompose idiosyncratic changes in income into predictable life-cycle changes, transitory and permanent shocks and estimate the contribution of each to total inequality. Our model fits the joint evolution of consumption and income inequality well and delivers two main results. First, we find that permanent changes in income explain all of the increase in inequality in the 1980s and 90s. Second, we reconcile this finding with the fact that consumption inequality did not increase much over this period. Our results support the view that many permanent changes in income are predictable for consumers, even if they look unpredictable to the econometrician, consistent with models of heterogeneous income profiles.

Consumption, inequality, risk, incomplete markets, heterogeneity

Abstract:
Was the increase in income inequality in the US due to permanent shocks or merely to an increase in the variance of transitory shocks? The implications for consumption and welfare depend crucially on the answer to this question. We use CEX repeated cross-section data on consumption and income to decompose idiosyncratic changes in income into predictable life-cycle changes, transitory and permanent shocks and estimate the contribution of each to total inequality. Our model fits the joint evolution of consumption and income inequality well and delivers two main results. First, we find that permanent changes in income explain all of the increase in inequality in the 1980s and 90s. Second, we reconcile this finding with the fact that consumption inequality did not increase much over this period. Our results support the view that many permanent changes in income are predictable for consumers, even if they look unpredictable to the econometrician, consistent with models of heterogeneous income profiles.

consumption, inequality, risk, incomplete markets, heterogeneity

Abstract:
In many countries, student grants, tuition fees, and subsidized loans depend on parental income. This paper examines the efficiency and distributional effects of such conditioning, and assesses whether it is optimal practice when the government wants to reduce after-tax income inequality in the most efficient manner. Increasing the mean level of education among the work-force compresses wage differentials by level of education and thereby the pre-tax income distribution. Hence, subsidizing education may be part of an optimal redistribution policy. However, education subsidies mainly benefit high-ability students, limiting their redistributive virtues. Conditioning education subsidies on parental income may enable the government to reduce inframarginal subsidies, mainly benefiting high-ability students, while preserving the marginal subsidy, and thus the favourable effect on the mean education level which leads to wage compression.