Using panel data allows accounting for country (and time) fixed effects (//, and //,). The country dummies are included to control for time-invariant omitted-variable bias, and the period dummies are included to control for global shocks, which might affect aggregate growth in any period but are not otherwise captured by the explanatory variables. Moreover, the analysis will exploit Generalised Method of Moments (GMM) as opposed to OLS or the Least Square Dummy Variable estimators (see Box 1 for a description).