This paper argues that mainstream economics does not follow the positivist research tradition it (often implicitly) claims to follow and expresses some serious doubt that econometrics in particular can make economics a hard science. Mathematical rigour and sophisticated statisti-cal techniques...

This paper presents a survey on panel data methods in which I emphasize new developements. In particular, linear multilevel models with a new variant are discussed. Furthermore, non-linear, nonparametric and semiparametric models are analyzed. In contrast to linear models there do not exist...

This paper considers factor estimation from heterogenous data, where some of the variables are noisy and only weakly informative for the factors. To identify the irrelevant variables, we search for zero rows in the loadings matrix of the factor model. To sharply separate these irrelevant...