is pooled ols regression significant why are the explanatory variables pooled why pooled ols is useful what is pooled ols why are OLS pools necessary what is important about pooled ols how important is ols what is significant in a pooled ols model does fe have pooled opers what is the difference of pooled ols and fixed effects what is pooled ols mean why is an OLS significant in pooled ols if the explanatory variable is always consistent what is the ols significant why is a pooled ols important what is the difference between pooled and random effects when using pooled ols can the effect of variable be overestimated what is pooled ols in fe regression what is the difference between a pooled ols and an unspecified ollis what is the difference between pooled ols and variable pooled ols can a pooled ollis be used instead of a fixed effect?