different result in two nb reg and pisson reg

Posted by Awan on Sep 14, 2014; 10:45pm
URL: http://spssx-discussion.165.s1.nabble.com/different-result-in-two-nb-reg-and-pisson-reg-tp5727252.html

Hi

I have a question about the differences between negative binominal regression and pisson regression. in my dateset the mean is not equal variance value, so I decided to run a nb reg, but by contrast to what I have heard about the same results for both models, my models copeletley different with each others. all of coeffiecents  are significant in pisson reg, but are not in negetive binominal. I have heard these two model reg, just different thecnicaly and are not different in result, it migh be some values are different but the results are same. but my results models' are different. could you please give me some addvice on this issue?
Awan