Recent studies indicate that firms often outsource standard and simple tasks, while keeping complex and important inputs inside their boundaries. This observation is difficult to reconcile with the property rights approach of the firm, which suggests that important components should be...

We develop a theory of a firm in an environment with incomplete contracts. The firm’s headquarter decides on the complexity, the organization, and the global scale of its production process. Specifically, it decides: i) on the mass of symmetric intermediate inputs that are part of the value...

We develop a general equilibrium model of international trade with heterogeneous firms, where countries can invest into basic research to improve their technological potential. These research investments tighten firm selection and raise the average productivity of firms in the market, thereby...

We analyze the first data set on consistently defined functional urban areas in Europe and compare the European to the US urban system. City sizes in Europe do not follow a power law: the largest cities are "too small" to follow Zipf's law.

In this paper we show that the recent model by Duranton (AER, 2007) performs remarkably well in replicating the city size distribution of West Germany, much better than the simple rank-size rule known as Zipf’s law. The main mechanism of this theoretical framework is the "churning" of...

In this paper we show that the double Pareto lognormal (DPLN) parameterization provides an excellent fit to the overall US city size distribution, regardless of whether "cities" are administratively defined Census places or economically defined area clusters. We then consider an economic model...

We investigate whether time-persistent cultural borders impede economic exchange across regions of the same country. To measure cultural differences we evaluate, for the first time in economics, linguistic micro-data about phonological and grammatical features of German dialects. These data are...

The salient rank-size rule known as Zipf's law is not only satisfied for Germany's national urban hierarchy, but also for the city size distributions in single German regions. To analyze this phenomenon, we build on the insights by Gabaix (1999) that Zipf's law follows from a stochastic growth...

During the last decade there have been marked changes in the composition of the non-native workforce in the German labour market. In particular there has been a notable increase in the diversity of nationalities of which the foreign workforce is composed. In this paper we investigate the effects...

We present a dynamic two-region model with overlapping generations. There are two types of public expenditure, education and infrastructure funding, and governments decide optimally on budget size (tax rate) and its allocation across the two outlays. Productivity of government infrastructure...