The idea of program evaluation is both simple and appealing. Program outcomes are measured and compared to some minimum performance standard or threshold. In practice, however, evaluation is difficult. Two fundamental problems of outcome measurement must be addressed. The first, which we call...

Institutions for collective decision making often defer to the status quo, granting it a privileged position relative to proposed policy innovations. The possible benefits of status quo deference must be weighed against a cost: status quo deference can prevent a society from learning the merits...

Public policy advocates routinely assert that “research has shown” a particular policy to be desirable. But how reliable is the analysis in the research they invoke? And how does that analysis affect the way policy is made, on issues ranging from vaccination to minimum wage to FDA drug...

Economists studying choice with partial knowledge typically assume that the decision maker places a subjective distribution on unknown quantities and maximizes expected utility. Someone lacking a subjective distribution faces a problem of choice under ambiguity. This article reviews recent...