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Reassessing the trends in the relative supply of college-equivalent workers in the U.S.: a selection-correction approach

Abstract

Among better-educated employed men, the fraction of full-time full-year (FTFY) workers is quite high and stable—around 90 percent—over time in the U.S. Among those with lower education levels, however, this fraction is much lower and considerably more volatile, moving within the range of 62–82 percent for high school dropouts and 75–88 percent for high school graduates. These observations suggest that the composition of unobserved skills may be subject to sharp movements within low-educated employed workers, while the scale of these movements is potentially much smaller within high-educated ones. The standard college-premium framework accounts for the observed shifts between education categories, but it cannot account for unobserved compositional changes within education categories. Our paper uses Heckman’s two-step estimator on repeated Current Population Survey cross sections to calculate a relative supply series that corrects for unobserved compositional shifts due to selection into and out of the FTFY status. We find that the well-documented deceleration in the growth rate of relative supply of college-equivalent workers after mid-1980s becomes even more pronounced once we correct for selectivity. This casts further doubt on the relevance of the plain skill-biased technical change (SBTC) hypothesis. We conclude that what happens to the within-group unobserved skill composition for low-educated groups is critical for fully understanding the trends in the relative supply of college workers in the United States. We provide several interpretations to our selection-corrected estimates.

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References

  1. 1.

    Acemoglu, D.: Why do new technologies complement skills? Directed technical change and wage inequality. Q. J. Econ. 113, 1055–1090 (1998)

    Article  Google Scholar 

  2. 2.

    Acemoglu, D.: Changes in unemployment and wage inequality: an alternative theory and some evidence. Am. Econ. Rev. 89, 1259–1278 (1999)

    Article  Google Scholar 

  3. 3.

    Acemoglu, D., Autor, D.: Skills, tasks, and technologies: implications for employment and earnings. In: Ashenfelter O., Card, D. (eds.) Handbook of Labor Economics, vol. 4, chap. 12, pp. 1043–1171. Elsevier, New York (2011)

  4. 4.

    Autor, D.H., Katz, L.F., Kearney, M.S.: Trends in U.S. wage inequality: revising the revisionists. Rev. Econ. Stat. 90, 300–323 (2008)

    Article  Google Scholar 

  5. 5.

    Autor, D.H., Katz, L.F., Krueger, A.B.: Computing inequality: have computers changed the labor market? Q. J. Econ. 113, 1169–1213 (1998)

    Article  Google Scholar 

  6. 6.

    Ben-Porath, Y.: The production of human capital and the life cycle of earnings. J. Pol. Econ. 75, 352–365 (1967)

    Article  Google Scholar 

  7. 7.

    Bound, J., Johnson, G.: Changes in the structure of wages in the 1980’s: an evaluation of alternative explanations. Am. Econ. Rev. 82, 371–392 (1992)

    Google Scholar 

  8. 8.

    Bowlus, A.J., Robinson, C.: Human capital prices, productivity, and growth. Am. Econ. Rev. 102, 3483–3515 (2012)

    Article  Google Scholar 

  9. 9.

    Browning, M., Hansen, L.P., Heckman, J.J.: Micro data and general equilibrium models. In: Taylor J.B., Woodford M. (eds.) Handbook of Macroeconomics, Elsevier, vol. 1A, chap. 8, pp. 543–633 (1999)

  10. 10.

    Card, D., DiNardo, J.E.: Skill-biased technical change and rising wage inequality: some problems and puzzles. J. Labor Econ. 20, 733–783 (2002)

    Article  Google Scholar 

  11. 11.

    Card, D., Lemieux, T.: Can falling supply explain the rising return to college for younger men? A cohort-based analysis. Q. J. Econ. 116, 705–746 (2001)

    Article  Google Scholar 

  12. 12.

    Carneiro, P., Lee, S.: Trends in quality adjusted skill premia in the United States, 1960–2000. Am. Econ. Rev. 101, 2309–2349 (2011)

    Article  Google Scholar 

  13. 13.

    Chamberlain, G.: Asymptotic efficiency in semiparametric models with censoring. J. Econ. 32, 189–218 (1986)

    Article  Google Scholar 

  14. 14.

    Ciccone, A., Papaioannou, E.: Human capital, the structure of production, and growth. Rev. Econ. Stat. 91, 66–82 (2009)

    Article  Google Scholar 

  15. 15.

    Davis, S.J., Haltiwanger, J.C.: Wage dispersion between and within U.S. manufacturing plants, 1963–1986. Brookings papers on economic activity: microeconomics, pp. 115–180 (1991)

  16. 16.

    DiNardo, J.E., Fortin, N.M., Lemieux, T.: Labor market institutions and the distribution of wages, 1973-1992: a semiparametric approach. Econometrica 64, 1001–1044 (1996)

    Article  Google Scholar 

  17. 17.

    Feenstra, R.C., Hanson, G.H.: The impact of outsourcing and high-technology capital on wages: estimates for the United States, 1979–1990. Q. J. Econ. 114, 907–940 (1999)

    Article  Google Scholar 

  18. 18.

    Heckman, J.J.: Shadow prices, market wages, and labor supply. Econometrica 42, 679–694 (1974)

    Article  Google Scholar 

  19. 19.

    Heckman, J.J.: Sample selection bias as a specification error. Econometrica 47, 153–161 (1979)

    Article  Google Scholar 

  20. 20.

    Heckman, J.J.: Varieties of selection bias. Am. Econ. Rev. 80, 313–318 (1990)

    Google Scholar 

  21. 21.

    Heckman, J.J., Lochner, L.J., Taber, C.: Explaining rising wage inequality: explorations with a dynamic general equilibrium model of labor earnings with heterogeneous agents. Rev. Econ. Dyn. 1, 1–58 (1998)

    Article  Google Scholar 

  22. 22.

    Hoynes, H.W., Miller, D.L., Schaller, J.: Who suffers during recessions? J. Econ. Perspect. 26, 27–48 (2012)

    Article  Google Scholar 

  23. 23.

    Iranzo, S., Peri, G.: Schooling externalities, technology, and productivity: theory and evidence from U.S states. Rev. Econ. Stat. 91, 420–431 (2009)

    Article  Google Scholar 

  24. 24.

    Katz, L.F., Autor, D.: Changes in the wage structure and earnings inequality. In: Ashenfelter, O., Card, D. (eds.) Handbook of Labor Economics, vol. 1, pp. 1463–1555, Elsevier, New York (1999)

  25. 25.

    Katz, L.F., Murphy, K.M.: Changes in relative wages, 1963-87: supply and demand factors. Q. J. Econ. 90, 35–78 (1992)

    Article  Google Scholar 

  26. 26.

    Krueger, A.B.: How computers have changed the wage structure: evidence from microdata, 1984–1989. Q. J. Econ. 108, 33–60 (1993)

    Article  Google Scholar 

  27. 27.

    Lee, D.S.: Wage inequality during the 1980s: rising dispersion or falling minimum wage? Q. J. Econ. 114, 977–1023 (1999)

    Article  Google Scholar 

  28. 28.

    Lemieux, T.: Increasing residual wage inequality: composition effects, noisy data, or rising demand for skill? Am. Econ. Rev. 96, 461–498 (2006)

    Article  Google Scholar 

  29. 29.

    Mincer, J.: Human capital, technology, and the wage structure: what do time series show? NBER Working Paper #3581 (1991)

  30. 30.

    Moffitt, R.A.: New developments in econometric methods for labor market analysis. In: Ashenfelter, O., Card, D. (eds.) Handbook of Labor Economics, vol. 3A, pp. 1367–1397, Elsevier, New York (1999)

  31. 31.

    Mulligan, C.B., Rubinstein, Y.: Selection, investment, and women’s relative wages over time. Q. J. Econ. 123, 1061–1110 (2008)

    Article  Google Scholar 

  32. 32.

    Newey, W.K.: Consistency of two-step sample selection estimators despite misspecification of distribution. Econ. Lett. 63, 129–132 (1999)

    Article  Google Scholar 

  33. 33.

    Park, J.H.: Estimation of sheepskin effects and returns to schooling using the old and the new cps measures of educational attainment. Industrial Relations Section WP#338, Princeton University (1994)

  34. 34.

    Violante, G.L.: Skill-biased technical change. In: Blume, L.E., Durlauf, S. N. (eds.) The New Palgrave Dictionary of Economics, 2 edn. MacMillan, New York (2008)

  35. 35.

    Weiss, Y., Lillard, L.A.: Experience, vintage, and time effects in the growth of earnings: American scientists, 1960–1970. J. Pol. Econ. 86, 427–447 (1978)

    Article  Google Scholar 

  36. 36.

    Willis, R.J., Rosen, S.: Education and self-selection. J. Pol. Econ. 87, S7—S36 (1979)

    Article  Google Scholar 

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Correspondence to Semih Tumen.

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Elitas, Z., Ercan, H. & Tumen, S. Reassessing the trends in the relative supply of college-equivalent workers in the U.S.: a selection-correction approach. J Econ Inequal 13, 249–273 (2015). https://doi.org/10.1007/s10888-014-9278-7

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Keywords

  • Wage inequality
  • Self selection
  • Relative supply index
  • College premium
  • SBTC
  • FTFY