This paper grew out of a lecture presented at the 54th Session of the International Statistical Institute in Berlin, August 13 - 20, 2003, Schneeweiss (2003). It intends not only to outline the eventful life of Abraham Wald (1902 - 1950) in Austria and in the United States but also to present...

Hans Schneeweiß is- one of the best-known German econometricians and statisticians. He was born in Glatz, Silesia, on March 13, 1933. Hans SchneeweiB studied mathematics and physics and received his Ph. D. degree from the Johann-Wolfgang-Goethe University, Frankfurt, in 1960. He was member of...

we prove that the quasi-score estimator in a mean-variance model is optimal in the class of (unbiased) linear score estimators, in the sense that the difference of the asymptotic covariance matrices of the linear score and quasi-score estimator is positive semi-definite. We also give conditions...