[Roberta Pilgrim]

Hi Clyde, I'm trying to formally explain the model I'm using: Unconditional Negative Binomial Fixed Effect.

This is the model I've used but I'm trying to clearly interpret all the terms.

• This log-linear specification ensures that λ will be greater than 0, regardless of what’s on the right-hand side
• μ_{t (mu) is an intercept}
• x_it are the time-varying predictor variables
• alphas are treated as a set of fixed coefficients (one for each individual)

Mu question is: why is the gamma in the model if it represents time-invariant variables???

Thank you so much in advance!