Productivity spillovers are often cited as a reason for geographic specialization in production. A large literature in medicine documents specialization across areas in the use of surgical treatments, which is unrelated to patient outcomes. We show that a simple Roy model of patient treatment...

We use simple economic insights to develop a framework for distinguishing between prejudice and statistical discrimination using observational data. We focus our inquiry on the enormous literature in healthcare where treatment disparities by race and gender are not explained by access,...

In medicine, the reasons for variation in treatment rates across hospitals serving similar patients are not well understood. Some interpret this variation as unwarranted, and push standardization of care as a way of reducing allocative inefficiency. An alternative interpretation is that...

I demonstrate that the literature on the racial wage gap has systematically overstated the gains made by African American men by ignoring their withdrawal from the labor force. Three sources of selection-bias are identified: imposing sample selection criteria based on labor supply, trimming...