Author Page for Claudia Goldin

1.

The U-Shaped Female Labor Force Function in Economic Development and Economic History

NBER Working Paper No. w4707

Number of pages: 49 Posted: 27 Jul 2000 Last Revised: 13 Nov 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 719 (72,177)

Citation 9

Abstract:

2.

The Origins of Technology-Skill Complementarity

Downloads 520 (108,616)

Citation 34

2

The Origins of Technology-Skill Complementarity

Number of pages: 40 Posted: 24 Oct 1996

Lawrence F. Katz and Claudia Goldin

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 467 (122,188)

Citation 4

Abstract:

The Origins of Technology-Skill Complementarity

NBER Working Paper No. w5657

Number of pages: 40 Posted: 27 Dec 2010 Last Revised: 18 Dec 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 53 (759,192)

Citation 30

Abstract:

3.

Marriage Bars: Discrimination Against Married Women Workers, 1920's to 1950's

NBER Working Paper No. w2747

Number of pages: 48 Posted: 09 Jun 2004 Last Revised: 06 Jul 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 513 (110,439)

Citation 1

Abstract:

4.

A Brief History of Education in the United States

NBER Working Paper No. h0119

Number of pages: 76 Posted: 01 Jun 2006 Last Revised: 01 May 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 449 (129,439)

Citation 4

Abstract:

5.

Dynamics of the Gender Gap for Young Professionals in the Corporate and Financial Sectors

NBER Working Paper No. w14681

Number of pages: 55 Posted: 31 Jan 2009 Last Revised: 14 Aug 2022

Marianne Bertrand, Claudia Goldin and Lawrence F. Katz

University of Chicago - Booth School of Business, Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 387 (153,713)

Citation 281

Abstract:

6.

The Role of World War Ii in the Rise of Women's Work

NBER Working Paper No. w3203

Number of pages: 29 Posted: 27 Apr 2000 Last Revised: 15 Feb 2002

Claudia Goldin

Harvard University - Department of Economics

Downloads 276 (220,861)

Citation 25

Abstract:

7.

The Race between Education and Technology: The Evolution of U.S. Educational Wage Differentials, 1890 to 2005

NBER Working Paper No. w12984

Number of pages: 48 Posted: 23 Mar 2007 Last Revised: 25 Dec 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 240 (253,808)

Citation 8

Abstract:

8.

Career and Family: College Women Look to the Past

NBER Working Paper No. w5188

Number of pages: 53 Posted: 13 Jul 2000 Last Revised: 05 Sep 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 230 (264,407)

Citation 7

Abstract:

9.

The Power of the Pill: Oral Contraceptives and Women's Career and Marriage Decisions

Downloads 182 (328,385)

Citation 137

2

The Power of the Pill: Oral Contraceptives and Women's Career and Marriage Decisions

NBER Working Paper No. w7527

Number of pages: 49 Posted: 05 May 2000 Last Revised: 28 Jul 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 182 (327,728)

Citation 137

Abstract:

The Power of the Pill: Oral Contraceptives and Women's Career and Marriage Decisions

Posted: 03 Dec 2002

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Abstract:

10.

Corruption and Reform: An Introduction

NBER Working Paper No. w10775

Number of pages: 27 Posted: 05 Oct 2005 Last Revised: 24 Aug 2009

Edward L. Glaeser and Claudia Goldin

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 181 (330,084)

Citation 9

Abstract:

11.

The Homecoming of American College Women: The Reversal of the College Gender Gap

NBER Working Paper No. w12139

Number of pages: 46 Posted: 18 May 2006 Last Revised: 26 Dec 2022

Claudia Goldin, Lawrence F. Katz and Ilyana Kuziemko

Harvard University - Department of Economics, Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 174 (341,758)

Citation 110

Abstract:

12.

The Rise of the Fourth Estate: How Newspapers Became Informative and Why it Mattered

NBER Working Paper No. w10791

Number of pages: 56 Posted: 06 Oct 2004 Last Revised: 28 Dec 2022

Matthew Gentzkow, Edward L. Glaeser and Claudia Goldin

University of Chicago - Booth School of Business, Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 160 (369,232)

Citation 4

Abstract:

13.

The Quiet Revolution that Transformed Women's Employment, Education, and Family

NBER Working Paper No. w11953

Number of pages: 50 Posted: 13 Apr 2006 Last Revised: 31 Aug 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 155 (377,110)

Citation 125

Abstract:

14.

Labor Markets in the Twentieth Century

NBER Working Paper No. h0058

Number of pages: 110 Posted: 08 Mar 2000 Last Revised: 01 Mar 2023

Claudia Goldin

Harvard University - Department of Economics

Downloads 126 (444,516)

Abstract:

15.

Cliometrics and the Nobel

NBER Working Paper No. h0065

Number of pages: 30 Posted: 08 Mar 2000 Last Revised: 08 Mar 2023

Claudia Goldin

Harvard University - Department of Economics

Downloads 125 (447,241)

Abstract:

16.

The Long Road to the Fast Track: Career and Family

NBER Working Paper No. w10331

Number of pages: 26 Posted: 12 Mar 2004 Last Revised: 25 Sep 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 124 (449,947)

Citation 10

Abstract:

17.

A Pollution Theory of Discrimination: Male and Female Differences in Occupations and Earnings

NBER Working Paper No. w8985

Number of pages: 42 Posted: 07 Jun 2002 Last Revised: 22 Jul 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 122 (455,511)

Citation 9

Abstract:

18.

The Great Compression: The Wage Structure in the United States at Mid- Century

NBER Working Paper No. w3817

Number of pages: 62 Posted: 07 Aug 2007 Last Revised: 08 Dec 2022

Claudia Goldin and Robert A. Margo

Harvard University - Department of Economics and Boston University - Department of Economics

Downloads 121 (458,426)

Citation 42

Abstract:

19.

The For-Profit Postsecondary School Sector: Nimble Critters or Agile Predators?

NBER Working Paper No. w17710

Number of pages: 45 Posted: 31 Dec 2011 Last Revised: 24 May 2023

David Deming, David James Deming, Claudia Goldin and Lawrence F. Katz

Academic Dean, Harvard University - Harvard Kennedy School (HKS), Harvard University - Harvard Kennedy School (HKS), Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 118 (467,298)

Citation 17

Abstract:

20.

Orchestrating Impartiality: The Impact of "Blind" Auditions on Female Musicians

NBER Working Paper No. w5903

Number of pages: 46 Posted: 16 Jul 2000 Last Revised: 20 Aug 2022

Claudia Goldin and Cecilia E. Rouse

Harvard University - Department of Economics and Princeton University - Industrial Relations Section

Downloads 115 (476,500)

Citation 15

Abstract:

21.

Can Online Learning Bend the Higher Education Cost Curve?

NBER Working Paper No. w20890

Number of pages: 13 Posted: 27 Jan 2015 Last Revised: 30 Jan 2022

David Deming, Claudia Goldin, Lawrence F. Katz and Noam Yuchtman

Academic Dean, Harvard University - Harvard Kennedy School (HKS), Harvard University - Department of Economics, Harvard University - Department of Economics and University of California, Berkeley - Haas School of Business

Downloads 114 (479,633)

Citation 20

Abstract:

22.

The Political Economy of Immigration Restriction in the United States, 1890 to 1921

NBER Working Paper No. w4345

Number of pages: 42 Posted: 15 Feb 2001 Last Revised: 17 Nov 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 113 (482,776)

Citation 12

Abstract:

23.

Why the United States Led in Education: Lessons from Secondary School Expansion, 1910 to 1940

NBER Working Paper No. w6144

Number of pages: 45 Posted: 10 Jun 2000 Last Revised: 17 Apr 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 111 (489,111)

Abstract:

24.

How America Graduated from High School: 1910 to 1960

NBER Working Paper No. w4762

Number of pages: 48 Posted: 13 Aug 2000 Last Revised: 08 Jul 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 109 (495,643)

Citation 3

Abstract:

25.

The Returns to Skill in the United States Across the Twentieth Century

NBER Working Paper No. w7126

Number of pages: 51 Posted: 29 Sep 1999 Last Revised: 23 Dec 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 109 (495,643)

Abstract:

26.

The Historical Evolution of Female Earnings Functions and Occupations

NBER Working Paper No. w0529

Number of pages: 41 Posted: 16 Jul 2004 Last Revised: 14 Dec 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 102 (523,561)

Citation 4

Abstract:

27.

The Meaning of College in the Lives of American Women: the Past One-Hundred Years

NBER Working Paper No. w4099

Number of pages: 52 Posted: 16 Jul 2004 Last Revised: 15 Sep 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 100 (530,666)

Abstract:

28.

Long-Run Changes in the U.S. Wage Structure: Narrowing, Widening, Polarizing

NBER Working Paper No. w13568

Number of pages: 39 Posted: 05 Nov 2007 Last Revised: 30 Jul 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 99 (530,666)

Citation 28

Abstract:

29.

From the Valley to the Summit: The Quiet Revolution that Transformed Women's Work

NBER Working Paper No. w10335

Number of pages: 31 Posted: 15 Mar 2004 Last Revised: 29 Sep 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 93 (552,479)

Citation 2

Abstract:

30.

The Shaping of Higher Education: The Formative Years in the United States, 1890 to 1940

NBER Working Paper No. w6537

Number of pages: 57 Posted: 11 Jun 2000 Last Revised: 13 Nov 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 90 (563,800)

Citation 10

Abstract:

31.

The Value of Postsecondary Credentials in the Labor Market: An Experimental Study

NBER Working Paper No. w20528

Number of pages: 53 Posted: 30 Sep 2014 Last Revised: 03 Feb 2023

David Deming, Noam Yuchtman, Amira Abulafi, Claudia Goldin and Lawrence F. Katz

Academic Dean, Harvard University - Harvard Kennedy School (HKS), University of California, Berkeley - Haas School of Business, affiliation not provided to SSRN, Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 87 (575,823)

Citation 17

Abstract:

32.

Life-Cycle Labor Force Participation of Married Women: Historical Evidence and Implications

NBER Working Paper No. w1251

Number of pages: 36 Posted: 09 Jun 2004 Last Revised: 04 Dec 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 84 (588,022)

Citation 1

Abstract:

33.

Mass Secondary Schooling and the State

NBER Working Paper No. w10075

Number of pages: 48 Posted: 12 Nov 2003 Last Revised: 14 Jul 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 82 (596,611)

Citation 1

Abstract:

34.

Women Working Longer: Facts and Some Explanations

NBER Working Paper No. w22607

Number of pages: 59 Posted: 07 Sep 2016 Last Revised: 10 Apr 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 77 (618,362)

Citation 5

Abstract:

35.

Monitoring Costs and Occupational Segregation by Sex: an Historical Analysis

NBER Working Paper No. w1560

Number of pages: 34 Posted: 19 Jun 2004 Last Revised: 08 Oct 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 75 (627,206)

Citation 3

Abstract:

36.

Making a Name

NBER Working Paper No. w8474

Number of pages: 27 Posted: 17 Sep 2001 Last Revised: 16 Apr 2022

Claudia Goldin and Maria Shim

Harvard University - Department of Economics and Maria Shim

Downloads 75 (627,206)

Abstract:

37.

The Human Capital Century and American Leadership: Virtues of the Past

NBER Working Paper No. w8239

Number of pages: 44 Posted: 20 Apr 2001 Last Revised: 08 Jul 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 75 (627,206)

Abstract:

38.

Human Capital and Social Capital: The Rise of Secondary Schooling in America, 1910 to 1940

NBER Working Paper No. w6439

Number of pages: 54 Posted: 06 Sep 2000 Last Revised: 07 Aug 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 75 (627,206)

Citation 3

Abstract:

39.

The "Virtues" of the Past: Education in the First Hundred Years of the New Republic

NBER Working Paper No. w9958

Number of pages: 59 Posted: 10 Sep 2003 Last Revised: 18 Sep 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 74 (631,770)

Abstract:

40.

Does Federal Student Aid Raise Tuition? New Evidence on For-Profit Colleges

NBER Working Paper No. w17827

Number of pages: 52 Posted: 10 Feb 2012 Last Revised: 19 Mar 2023

Stephanie Riegg Cellini and Claudia Goldin

George Washington University - School of Public Policy and Public Administration (SPPPA) and Harvard University - Department of Economics

Downloads 73 (636,410)

Citation 19

Abstract:

41.

The Earnings Gap between Male and Female Workers: an Historical Perspective

NBER Working Paper No. w1888

Number of pages: 43 Posted: 07 Jul 2004 Last Revised: 31 Aug 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 73 (636,410)

Abstract:

42.

The Rising (and then Declining) Significance of Gender

NBER Working Paper No. w8915

Number of pages: 48 Posted: 25 Apr 2002 Last Revised: 12 Nov 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 71 (645,952)

Citation 1

Abstract:

43.

Women, Children, and Industrialization in the Early Republic: Evidence from the Manufacturing Censuses

NBER Working Paper No. w0795

Number of pages: 53 Posted: 04 Mar 2007 Last Revised: 06 Mar 2022

Claudia Goldin and Kenneth L. Sokoloff

Harvard University - Department of Economics and University of California, Los Angeles (UCLA) - Department of Economics

Downloads 70 (650,905)

Citation 3

Abstract:

44.

Shocking Labor Supply: A Reassessment of the Role of World War Ii on U.S. Women's Labor Supply

NBER Working Paper No. w18676

Number of pages: 34 Posted: 09 Jan 2013 Last Revised: 14 Jul 2023

Claudia Goldin and Claudia Olivetti

Harvard University - Department of Economics and Boston College

Downloads 69 (655,579)

Citation 63

Abstract:

45.

The Relative Productivity Hypothesis of Industrialization: The American Case, 1820-1850

NBER Working Paper No. w0722

Number of pages: 36 Posted: 18 Aug 2004 Last Revised: 24 Dec 2022

Claudia Goldin and Kenneth L. Sokoloff

Harvard University - Department of Economics and University of California, Los Angeles (UCLA) - Department of Economics

Downloads 68 (660,423)

Citation 13

Abstract:

46.

The Decline of Non-Competing Groups: Changes in the Premium to Education, 1890 to 1940

NBER Working Paper No. w5202

Number of pages: 57 Posted: 27 Jun 2000 Last Revised: 19 Sep 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 65 (675,601)

Abstract:

47.

A Distinctive System: Origins and Impact of U.S. Unemployment Compensation

NBER Working Paper No. w5889

Number of pages: 53 Posted: 07 Jul 2000 Last Revised: 06 Aug 2022

Katherine Baicker, Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Health Policy & Management, Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 64 (680,706)

Citation 1

Abstract:

48.

Education and Income in the Early 20th Century: Evidence from the Prairies

NBER Working Paper No. w7217

Number of pages: 51 Posted: 07 May 2000 Last Revised: 22 Sep 2022

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 63 (685,951)

Citation 1

Abstract:

49.

Economic Well-Being and Child Labor: The Inter Action of Family and Industry

NBER Working Paper No. w0707

Number of pages: 46 Posted: 29 Dec 2000 Last Revised: 09 Dec 2022

Claudia Goldin and Donald O. Parsons

Harvard University - Department of Economics and George Washington University

Downloads 62 (691,285)

Abstract:

50.

What Can Uwe Do for Economics?

NBER Working Paper No. w24189

Number of pages: 19 Posted: 09 Jan 2018 Last Revised: 04 Feb 2023

Tatyana Avilova and Claudia Goldin

Columbia University and Harvard University - Department of Economics

Downloads 54 (736,557)

Citation 22

Abstract:

51.

Putting the Co in Education: Timing, Reasons, and Consequences of College Coeducation from 1835 to the Present

NBER Working Paper No. w16281

Number of pages: 53 Posted: 24 Aug 2010 Last Revised: 28 Jun 2023

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 53 (742,683)

Citation 3

Abstract:

52.

The Most Egalitarian of All Professions: Pharmacy and the Evolution of a Family-Friendly Occupation

NBER Working Paper No. w18410

Number of pages: 42 Posted: 22 Sep 2012 Last Revised: 22 Apr 2023

Claudia Goldin and Lawrence F. Katz

Harvard University - Department of Economics and Harvard University - Department of Economics

Downloads 52 (749,039)

Citation 35

Abstract:

53.

Seasonality in Nineteenth Century Labor Markets

NBER Working Paper No. h0020

Number of pages: 41 Posted: 13 Nov 2007 Last Revised: 22 Jan 2023

Stanley L. Engerman and Claudia Goldin

University of Rochester - Department of Economics and Harvard University - Department of Economics

Downloads 52 (749,039)

Abstract:

54.

Appendix to: "How America Graduated from High School, 1910 to 1960", Construction of State-Level Secondary School Data

NBER Working Paper No. h0057

Number of pages: 25 Posted: 08 Mar 2000 Last Revised: 27 Feb 2023

Claudia Goldin

Harvard University - Department of Economics

Downloads 52 (749,039)

Abstract:

55.

The Work and Wages of Single Women: 1870 to 1920

NBER Working Paper No. w0375

Number of pages: 13 Posted: 22 Feb 2001 Last Revised: 13 Jul 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 51 (755,284)

Citation 1

Abstract:

56.

Xx>Xy?: The Changing Female Advantage in Life Expectancy

NBER Working Paper No. w24716

Number of pages: 49 Posted: 18 Jun 2018 Last Revised: 15 Jul 2023

Claudia Goldin and Adriana Lleras-Muney

Harvard University - Department of Economics and Princeton University - Princeton School of Public and International Affairs

Downloads 50 (761,693)

Citation 4

Abstract:

57.

How Japan and the Us Can Reduce the Stress of Aging

NBER Working Paper No. w22445

Number of pages: 27 Posted: 25 Jul 2016 Last Revised: 01 May 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 49 (768,251)

Abstract:

58.

Wages, Prices, and Labor Markets Before the Civil War

NBER Working Paper No. w3198

Number of pages: 36 Posted: 08 Jan 2008 Last Revised: 29 Sep 2022

Claudia Goldin and Robert A. Margo

Harvard University - Department of Economics and Boston University - Department of Economics

Downloads 47 (781,508)

Abstract:

59.

The Poor at Birth: Infant Auxology and Mortality at Philadelphia's Almshouse Hospital, 1848-1873

NBER Working Paper No. w2525

Number of pages: 32 Posted: 16 Jul 2004 Last Revised: 27 Nov 2022

Claudia Goldin and Robert A. Margo

Harvard University - Department of Economics and Boston University - Department of Economics

Downloads 41 (824,470)

Citation 2

Abstract:

60.

The Savings of Ordinary Americans: The Philidelphia Saving Fund Society in the Mid-Nineteenth Century

NBER Working Paper No. w4126

Number of pages: 39 Posted: 16 Jul 2004 Last Revised: 12 Oct 2022

George Alter, Claudia Goldin and Elyce Rotella

Indiana University Bloomington - Department of History, Harvard University - Department of Economics and Indiana University Bloomington - Department of Economics

Downloads 41 (824,470)

Citation 3

Abstract:

61.

The New Lifecycle of Women's Employment: Disappearing Humps, Sagging Middles, Expanding Tops

NBER Working Paper No. w22913

Number of pages: 39 Posted: 12 Dec 2016 Last Revised: 09 Feb 2023

Claudia Goldin and Joshua Mitchell

Harvard University - Department of Economics and Government of the United States of America - Bureau of the Census

Downloads 40 (832,075)

Citation 35

Abstract:

62.

Maximum Hours Legislation and Female Employment in the 1920s: a Reasse Ssment

NBER Working Paper No. w1949

Number of pages: 29 Posted: 16 Jun 2004 Last Revised: 01 May 2022

Claudia Goldin

Harvard University - Department of Economics

Downloads 40 (832,075)

Citation 8

Abstract:

63.

Watersheds in Child Mortality: The Role of Effective Water and Sewerage Infrastructure, 1880 to 1920

NBER Working Paper No. w21263

Number of pages: 48 Posted: 15 Jun 2015 Last Revised: 06 Feb 2022

Marcella Alsan and Claudia Goldin

Harvard University - Harvard Kennedy School (HKS) and Harvard University - Department of Economics

Downloads 25 (964,679)

Citation 51

Claudia Goldin

Harvard University - Department of Economics

Professor of Economics

National Bureau of Economic Research (NBER)

63

Top 11,868

8,106

Top 596

1,221

Scholarly Papers (63)

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract:

Abstract: