zip¶ Fit a zero-inflated Poisson count-response model with a logit inflation equation. When to use How do I model count outcomes with excess zeros and a separate zero-generation process? Syntax¶ zip y x1 x2, inflate(z1 z2) [robust cluster(var) noconstant] Examples¶ zip visits age income, inflate(age income) zip claims age exposure, inflate(exposure) robust See also¶ Command Reference Index User Guide In-App Help System