v 2 d trpois0. Zero-truncated Poisson regression. d Program by Joseph Hilbe, Arizona State Univ. d d Module to estimate zero-truncated Poisson regression models d trpois0 estimates maximum likelihood zero-truncated Poisson d regression models using Stata's ml method for estimation. A d 0-truncated Poisson model is appropriate when modeling count d data which does not have zero values. d d See help trpois0. f trpois0/trpois0.hlp f trpois0/trpois0.ado f trpois0/trpoislf.ado