Stata Panel Data 'link' Jun 2026

Pooled OLS ignores the panel structure entirely. It treats all observations as independent.

xtreg y x1 x2 x3 i.year, fe

Stata offers three foundational models for panel regression: Pooled OLS, Fixed Effects, and Random Effects. Pooled OLS

Before you can run any panel models, your dataset must be organized in a "long" format, where each row represents a unique combination of an entity ( ) and a time period ( stata panel data

When you run xtreg, fe , Stata automatically includes an F-test at the bottom of the output: F test that all u_i=0 .

A robust Stata workflow for panel data involves several key stages. For clarity, these stages are summarized below:

1:1 because each combination is unique.

Do you suspect or cross-sectional correlation in your sample?

xtlogit emp wage hours, fe margins, dydx(*) atmeans

xtunitroot llc wage, trend lags(2) // Levin-Lin-Chu xtunitroot ips wage, trend lags(2) // Im-Pesaran-Shin xtunitroot fisher wage, trend lags(2) // Fisher-type Pooled OLS ignores the panel structure entirely

Measures how much the average values differ across units.

Standard errors can be falsely precise if observations within the same unit are correlated over time. To obtain robust inference, use clustered standard errors: xtreg y x1 x2 x3, fe vce(cluster panelvar) Use code with caution.