The "collapse" suboption to prevent "instrument proliferation"—a common pitfall that weakens the validity of your results. 4. Advanced Visualization for Panel Data
When running a regression, you must drop one category to serve as the (base case). If you include all exclusive dummies plus the constant term, you will introduce perfect multicollinearity.
Static models assume no lagged dependent variable. The three workhorses are , fixed effects (FE) , and random effects (RE) . The core estimation command is xtreg . stata panel data exclusive
quietly xtreg y x1 x2, fe estimates store fixed quietly xtreg y x1 x2, re estimates store random hausman fixed random Use code with caution.
Once declared, these commands become available: If you include all exclusive dummies plus the
Panel data usually stored (one row per id‑year). To convert from wide:
By mastering these commands, researchers can perform a wide range of panel data analysis tasks in Stata. The core estimation command is xtreg
: Determines if a Fixed Effects or Random Effects model is more appropriate. Rejection of the null ( ) favors Fixed Effects. Modified Wald Test