Over the last four decades, several methods for selecting the smoothing parameter, generally called the bandwidth, have been introduced in kernel regression. They differ quite a bit, and although there already exist more selection methods than for any other regression smoother we can still see...

The Africa-Dummy has been identfied and different explanations for its appearance have been published. In this paper, the issue of the empirical identifcation of the Africa-Dummy is addressed. We introduce a fixed eff ects regression model to identify the Africa-Dummy in one regression step so...