We propose various semiparametric estimators for nonlinear selection models, where slope and intercept can be separately identifed. When the selection equation satisfies a monotonic index restriction, we suggest a local polynomial estimator, using only observations for which the marginal...

Do regions converge? This essay provides an overview of the key developments in the study of regional convergence, discussing the methodological issues that have arisen since the first attempts to analyse convergence and critically surveying the results that have been obtained for different...