"High rates of understatement are found for many government transfer programs and in many datasets. This understatement has major implications for our understanding of economic well-being and the effects of transfer programs. We provide estimates of the extent of under-reporting for ten transfer...

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...