Stata Panel Data -

To run this test in Stata, estimate both models sequentially and save their results:

Sometimes, unobserved factors affect all entities simultaneously in a given time period (e.g., a global recession or a technological shift). You can include in both FE and RE models by adding i.year to the regressor list:

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

Because panel data has a time dimension, you often need to create lagged or differenced variables. You can do this using Stata's , which work after xtset : stata panel data

Autocorrelation makes standard errors deceptively small. Test for it using the Wooldridge test via the xtserial command: ssc install xtserial xtserial y x1 x2 Use code with caution. The Universal Fix: Robust Standard Errors

What or industry dataset are you currently working with?

If your data is in wide format (e.g., separate columns for income2020, income2021), use the reshape command: reshape long income, i(id) j(year) Use code with caution. Declaring the Panel Structure Tell Stata which variable identifies the entities ( ) and which identifies the time periods ( ) using the xtset command: xtset id year Use code with caution. To run this test in Stata, estimate both

If the , reject the null. Random effects are present. Step 3: Fixed Effects vs. Random Effects (Hausman Test)

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

[Your Name] Date: April 12, 2026

When one or more regressors are endogenous, you can use instrumental variables in a panel context. xtivreg supports FE, RE, and first‑differences IV estimators:

For categorical or binary variables, xttab conducts panel tabulations, showing how frequently units transition between states over time: xttab employment_status Use code with caution. 3. Core Panel Data Regression Models

If your data is in a wide format, convert it using the reshape command: reshape long income, i(id) j(year) Use code with caution. Setting the Panel Structure You can do this using Stata's , which