·“Shadow Prices,Market Wages and Labour Supply",Econometrica 42(4),1974,P679-694 发现并提出“选择性样本”问题。 "Sample Selection Bias as a Specification Error",Econometrica 47(1),1979,P153-161 证明了偏误的存在并提出了Heckman两步修正法。• “Shadow Prices, Market Wages and Labour Supply”, Econometrica 42 (4), 1974, P679-694 发现并提出“选择性样本”问题。 • “Sample Selection Bias as a Specification Error”, Econometrica 47(1), 1979, P153-161 证明了偏误的存在并提出了Heckman两步修正法