1. What are the special features of (a) cross-section data, (b) time series
data, and (c) panel data?
2. What is meant by a ?xed effects model (FEM)? Since panel data have both time and space dimensions, how does FEM allow for both dimensions?
3. What is meant by an error components model (ECM)? How does it differ from FEM? When is ECM appropriate? And when is FEM appropriate?
4. Is there a difference in FEM, least-squares dummy variable (LSDV) model, and covariance model?