In this paper, we assess whether welfare reform affects earnings only through mean impacts that are constant within but vary across subgroups. This is important because researchers interested in treatment effect heterogeneity typically restrict their attention to estimating mean impacts that are...

In this paper, we assess whether welfare reform affects earnings only through mean impacts that are constant within but vary across subgroups. This is important because researchers interested in treatment effect heterogeneity typically restrict their attention to estimating mean impacts that are...

A principal agent model in an entrepreneurial settingis developed and tested using Federal Reserve Board data on entrepreneurialeffort and wealth in privately held firms. The implications of agency theoryare tested based on three questions: (1) What determines the entrepreneur'sequity share? (2)...