In this paper we show that findings of an apparently instable popularity function of U.S. presidents, as reported in the previous literature, are likely the consequence of the common use of linear estimation techniques. Employing Penalized Spline Smoothing in the context of Additive Mixed Models...

As communication costs fall, foreign embassies and consulates have lost much of their role in decision-making and information-gathering. Accordingly, foreign services are increasingly marketing themselves as agents of export promotion. I investigate whether exports are in fact systematically...