We ask whether a PAYG-financed social security system is welfare improving in an economy with idiosyncratic and aggregate risk. We argue that interactions between the two risks are important for this question. One is a direct interaction in the form of a countercyclical variance of idiosyncratic...

When markets are incomplete, social security can partially insure against idiosyncratic and aggregate risks. We incorporate both risks into an analytically tractable model with two overlapping generations and demonstrate that they interact over the life-cycle. The interactions appear even though...

When markets are incomplete, social security can partially insure against idiosyncratic and aggregate risks. We incorporate both risks into an analytically tractable model with two overlapping generations. We derive the equilibrium dynamics in closed form and show that joint presence of both...

We propose a unified framework to measure the effects of different reforms of the pension system on retirement ages and macroeconomic indicators in the face of demographic change. A rich overlapping generations (OLG) model is built and endogenous retirement decisions are explicitly modeled...

Kaum eine ordnungspolitische oder regulatorische Frage hat in der deutschen Telekommunikationsbranche wohl in den letzten Jahren für so viel Aufruhr gesorgt, wie die Einführung des neuen §9a in das Telekommunikationsgesetz (TKG). Die neue Vorschrift sieht vor, dass die Bundesnetzagentur...

This paper provides a hedonic price analysis of mobile telephones for the German market. We have assembled data on 302 different handsets from 25 manufacturers over the period from May 1998 to November 2003. While volume has a negative effect on the price of a mobile handset, the number of...