I really like this Atlantic piece on the reality of food stamp (a.k.a. SNAP) participation. Economists tend not to pay much attention to program aspects other than benefit levels and eligibility rules, but they can matter. High time costs, incomprehensible communications from the program, and uncertainty of benefits can all deter participation conditional on eligibility.
One can try to frame some of this as an effort to induce self-sorting among the eligible between the more and less deserving (it acts as an "ordeal mechanism" in the technical jargon) but my guess is that at least some facets of the process deter the worst off among the eligible rather than the best off.
Plus it is just not very nice, as a society, to make the lives of poor people even more unpleasant and uncertain.
Who was my favorite student this term?
4 years ago