//-->
Unobserved Ability, Efficiency Wages, and Interindustry Wage Differentials
Blackburn, McKinley L., (1992)
Are OLS Estimates of the Return to Schooling Biased Downward? Another Look
Neumark, David, (1993)
Omitted-Ability Bias and the Increase in the Return to Schooling
Neumark, David, (1991)