# How to interpret this SAS poisson regression output?

I have a dependent variable being positive, discrete (number of people migrated) and the independent variables are all continuous. I want to study the impact of the independent variables on the dependent one to see what factors are shaping migration. The independent variable and some of the independent ones are heavily positively skewed (skewness around 4, QQ plot does not indicate normality). Also, correlation between predictor variables is present (colinerarity). These reasons led me to choose a GLM poisson regression with the log link function SAS using proc genmod.

I have two questions:

1. Why is deviance 0 and Pearson Chi-Square missing in the below output? Does this mean the model is not suitable for the data? If yes, what tests do exist to find out what model is suitable.

1. In the Parameter Estimation output, some of my variables are shown as highly significant (Pr>ChiSq of <.0001), even if they not correlated with the dependent variable using a simple (Pearson) correlation. Should I be concerned or am I comparing two different things?

Note: when running an OLS regression, none of the variables is shown as highly significant. What model should I believe?

• How many variables do you have? Jul 7, 2021 at 17:10
• I have 40 variables. A lot of them redundant. I removed the correlated variables, used negative binomial model instead of poisson and I got better results (deviance 1.5). But depending on what variable I add or remove, the parameter significance changes – Jul 8, 2021 at 13:22