I'm comparing a possion regression model (using glm) under R with same model (using poisson) and same data in Stata. Poisson GLM iteration using R has what it calls "deviance" values Deviance = 1711.706 Iterations - 1 Deviance = 1451.352 Iterations - 2 Deviance = 1442.306 Iterations - 3 Deviance = 1442.283 Iterations - 4 Poisson GLM iteration using Stata gives log likelihood values (0) -1567 (1) -1566 (2) -1566 As you can see, the R deviance values arent -2 * log likelihood values in Stata. Any idea how R calculates its deviance values? Many thanks.. Phil -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._