Quantitative policy evaluation can benefit from a rich set of econometric methods for analyzing count **data** Keywords: Poisson regression, negative binomial distribution, zero-inflation, hurdle model Pros Count **data** regressions provide an appropriate, rich, and flexible modeling environment for nonnegative integers, 0, 1, 2, etc. Poisson regression is the workhorse model for estimating constant relative policy effects. Hurdle and related models allow distinguishing between extensive margin effects (outcome probability of a zero) and intensive margin effects (probability of one or more counts). With count data, policy evaluations can move beyond the consideration of mean effects and determine the effect on the entire distribution of outcomes instead.