Tests cov(u_i, X) = 0. Null favors RE.
estat sargan // overidentification test (H0: valid) estat abond // Arellano-Bond AR(2) test (H0: no serial correlation)
vce(cluster id year) // Stata 17+ // Or use ivreg2 with cluster(id year) stata panel data exclusive
This will estimate a dynamic panel model of y on its own lag, x1 , and x2 .
Panel data, also known as longitudinal data, tracks the same cross-sectional units (individuals, firms, countries) over multiple time periods. While basic Stata commands like xtreg are widely known, mastering panel data requires moving beyond the basics into exclusive, advanced territory. Tests cov(u_i, X) = 0
What and industry/field data are you working with? What are the dimensions of your data ( sample size and time periods )?
: Controls for all time-invariant confounding factors, even if they are unobserved or unmeasured. Random Effects (RE) Panel data, also known as longitudinal data, tracks
Stata’s xtreg with fd option:
Ignores panel structure – use only as reference.
To help me tailor this script to your specific research project, please let me know: What are your primary ?
: If either heteroskedasticity or serial correlation is present, re-estimate your model using clustered standard errors at the unit level: xtreg income investment leverage, fe vce(cluster firm_id) Use code with caution.