The convergence hypothesis in growth theory implies that the frequency of the density distribution of GDP in a cross-section of countries tends to approach unimodality as we move forward in time. The convergence theory in a cross-section of 119 countries is tested by means of bootstrap...

Let (X,Y) be a pair of random variables with supp(X) \subseteq [0,1]?I and EY?2 \infinity. Let m* be the best approximation of the regression function of (X,Y) by sums of functions of at most d variables (formula). Estimation of m* from i.i.d. data is considered. For the estimation interaction...