Using newly available data at the firm level, this study provides convincing evidence of the importance of financial constraints in explaining the timing of innovations in the German services sector. Based on a dynamic model of firms' optimal R&D behavior under financial constraints, we estimate...

The simple Ricardian model explains the comparative cost advantage by a relative productivity advantage of the single factor of production. This model is tested in this paper using microdata of the german business survey. In a first approach labour is being considered to be the only factor of...

This paper compares various models for time series of counts which can account for discreetness, overdispersion and serial correlation. Besides observation- and parameter-driven models based upon corresponding conditional Poisson distributions, we also consider a dynamic ordered probit model as...