In this paper it is tested which of the various alternative approaches for constructing knowledge spillover pools suggested in existing literature measures the extent to which a firm can costlessly receive external knowlegde best. Since knowledge spillovers are unmeasurable, a 'goodness of fit'...

We analyze the performance of firms in the German business-related services sector. A quarterly business survey provides the panel data base of our study. Firm performance is measured by the survey respondents' ordinal indication of their changes in total sales. We use a firstorder Markov chain...