Dear all,

I am estimating a random-effects Poisson regression with Gamma distribution, using -xtpoisson, re-. The output shows the parameters alpha and /lnalpha. What are these exactly?

The help-file of -xtpoisson- mentions that "the exponentiated random effects are distributed as gamma with mean one and variance alpha". It later mentions that "follows a gamma distribution with mean one and variance 1/theta". This confuses me, because there are many ways of parametrizing Gamma distributions, including the parameters alpha, beta, lambda, mu, theta, and k. Any explanation would be welcomed.