17  D2. Panel Data — Overview

17.1 About

This section introduces panel data econometrics — data combining \(N\) units observed over \(T\) periods. This structure allows controlling for unobserved time-invariant heterogeneity, a key advantage over pure cross-sections.

Topics: one-way error component model, Fixed Effects (within estimator), Random Effects (GLS), Hausman test, first-difference estimator, dynamic panels (Arellano-Bond).

17.2 Lecture Notes

 

17.3 Slides

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Note: Slides and notes are pending translation to English.


17.4 Overview

Panel data (also called longitudinal data) combines cross-sectional and time series dimensions: we observe \(N\) units (individuals, firms, countries) over \(T\) time periods. This structure allows us to control for unobserved heterogeneity that is constant within a unit — a key advantage over pure cross-sections.

Key topics covered

  • The one-way error component model: \(y_{it} = x_{it}'\beta + \alpha_i + u_{it}\)
  • Fixed Effects (FE) — within estimator, FWL theorem applied to panels
  • Random Effects (RE) — GLS estimator, feasible GLS
  • Hausman test: FE vs. RE
  • First-difference estimator
  • Clustered standard errors
  • Dynamic panel models (GMM-based: Arellano-Bond)

More detail

See D3. Panel Data Theory for derivations and proofs.