st: pooled regression vs fixed effects

[Ozgur Ozdemir <ozdemirozgur@hotmail.com>]

Hi,
I am trying to address the multiple directorships association with firm performance however having difficulties to find which method to use. for example, when I do the following test on my panel data which has companies and years as index.
xi : areg tobin_q market_value logboard_size average_directorships_per_director i.year, robust absorb(industry)
I got all the independent variables significant however when I use the fixed effect model which seems more convient than the random effects based on the hausman test, 

xi : xtreg tobin_q market_value logboard_size average_directorships_per_director  i.icb_suprsectr_code i.year, robust fe

I got most of them insignificant. I am having difficulties to understand the reason and any help will be appreciated. I expect that the results should be similar in both cases as I have the same dummies across the year. however, do not have sufficient information about what areg really do ?   kind regardsOzgur Ozdemir 		 	   		  
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