The effect of innovations on employment at the firm level is theoretically ambiguous. The present paper analyses this relationship using panel data on German start-up firms as well as German patent data. It employs different indicators of patenting activity. By applying fixed-effects and...

This paper uses Granger non{causality tests to analyze if channel competition exists between the companion websites of 93 German newspapers observed between I/1998 and II/2005. It provides econometric evidence for significant negative effects of companion website tra?c on the print circulation...

We analyze the relationship between website visits, magazine demand and the demand for advertising pages using Granger non-causality tests on the ba- sis of an extensive and externally audited quarterly data set for the German magazine market spanning the period I/1998 to II/2004. We use...

In this paper, we use longitudinal data on Self-Reported Health Status from the Panel Study of Income Dynamics to estimate a model of the evolution of health over the life-cycle. The model allows for two sources of persistence in health: unobserved heterogeneity, which models an individual’s...

We analyze the relationship between website visits, magazine demand and the demand for advertising pages using Granger non-causality tests on the basis of an extensive and externally audited quarterly data set for the German magazine market spanning the period I/1998 to II/2004. We use...

We examine the effects of aid on growth-- in cross-sectional and panel data--after correcting for the bias that aid typically goes to poorer countries, or to countries after poor performance. Even after this correction, we find little robust evidence of a positive (or negative) relationship...

The estimation of regressions models with two-way error component disurbances, is considered for the case where both the random effects are non-spherically distributed. The usual approach that first transforms the effects into uncorrelated ones and then applies within and between...