This will test whether the fixed-effects or random-effects model is more appropriate.
Transforms all regressors via first-differencing to remove fixed effects, using deeper lags of the dependent variable as instruments.
xtreg y x1 x2, fe vce(cluster id)
Panel data often exhibit cross-sectional dependence due to common shocks, spatial spillovers, or network effects. The community-contributed xtcsd command tests for this:
Before accessing any exclusive panel features, the data must be defined as panel data. This is the gateway command that informs Stata of the cross-sectional and time-series dimensions. stata panel data exclusive
Note: The standard hausman command assumes homoskedasticity. If you are using robust or clustered standard errors, use the user-written xtoverid or vce(robust) combined with a Mundlak approach. 4. Diagnostic Testing for Panel Data
use mydata.dta, clear xtset id year
ssc install xtabond2 xtabond2 y L.y x1 x2, gmm(L.y) iv(x1 x2) nolevel small Use code with caution. System GMM (Blundell-Bond)
There is no unconditional fixed effects probit model in Stata due to the "incidental parameters problem," which yields inconsistent estimates. Stick to xtlogit, fe when you need to control for fixed effects with a binary outcome. Panel Count Data (Poisson and Negative Binomial) This will test whether the fixed-effects or random-effects
It allows unobserved heterogeneity to be correlated with your independent variables ( Xitcap X sub i t end-sub