Panel Data

[mtahir50]

Hi,
I have a question. I am using Panel data for 67 cross sections having four data points for each cross sections. I have four 5 interdependent variables in my model. The Hausman specification test suggests to use fixed effects model. Now i wanna know about the period fixed effects, whether to include it or not? Is there test to decide whether to estimate the model with both time fixed effects as well as cross section fixed effects? Thanks