Publication Date: September 2003
Revision Date: June 2004
Explicit asymptotic bias formulae are given for dynamic panel regression estimators as the cross section sample size N → ∞. The results extend earlier work by Nickell (1981) and later authors in several directions that are relevant for practical work, including models with unit roots, deterministic trends, predetermined and exogenous regressors, and errors that may be cross sectionally dependent. The asymptotic bias is found to be so large when incidental linear trends are ﬁtted and the time series sample size is small that it changes the sign of the autoregressive coeﬀicient. Another ﬁnding of interest is that, when there is cross section error dependence, the probability limit of the dynamic panel regression estimator is a random variable rather than a constant, which helps to explain the substantial variability observed in dynamic panel estimates when there is cross section dependence even in situations where N is very large. Some proposals for bias correction are suggested and ﬁnite sample performance is analyzed in simulations.
Autoregression, Bias, Bias correction, Cross section dependence, Dynamic factors, Dynamic panel estimation, Incidental trends, Panel unit root
JEL Classification Codes: C33Panel Data
See CFP: 1204