Did expanding medicaid affect welfare participation?

In a widely cited 1995 paper, Aaron Yelowitz concluded that Medicaid eligibility expansions for children were associated with increased labor force participation and reduced welfare participation among single mothers. The authors of the present study, using data from the 1988-96 Current Population Surveys, re-examine the evidence presented by Yelowitz. They find that Yelowitz's results resulted from two factors: he imposed a restriction on the parameter estimates not predicted by theory and rejected in the data, and he used only one of two income tests that families must pass to be eligible for welfare. The authors conclude that there is no evidence detectable in the CPS data of a relationship between welfare or labor force participation and the Medicaid income limits.