Visual inspection is crucial. xtline produces time‑series plots for each unit. To plot the first 10 individuals:
Explains variation between panels, not within.
A significant test statistic indicates that the error variance differs across panels.
Alternatively, using areg or reghdfe (for high-dimensional FE): stata panel data
: Plot time series for multiple entities at once. Command: xtline variable_name 3. Model Estimation
Do you expect your key variables to change , or are they static ?
Before typing a single command, you must grasp how Stata "thinks" about panel data. Visual inspection is crucial
Serial correlation skews standard errors, making your coefficients look more statistically significant than they actually are. Use the Wooldridge test for autocorrelation (requires xtserial ). ssc install xtserial xtserial GDP inflation trade_openness Use code with caution.
xtsum ln_wage hours age
asdoc xtreg wage experience union i.year, fe A significant test statistic indicates that the error
Fixed Effects (preferred due to ability bias) xtreg wage union experience i.year, fe robust
Stata offers three primary linear frameworks for analyzing panel data: Pooled OLS, Fixed Effects, and Random Effects. Pooled OLS (Ordinary Least Squares)
: Before running any analysis, you must tell Stata your data is a panel using xtset : xtset country_id year 2. Exploring and Visualizing