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...

This paper analyses regional growth in Eastern Europe in the second half of the 1990s, when regional disparities sharply increased. We aim to identify the factors behind growth and investigate in particular the role of (foreign) investment, education and innovation as well as geographical...