The division of labor between and within countries is driven by two fundamental forces, comparative advantage and increasing returns. We set up a simple Ricardian model with a Marshallian input sharing mechanism to study their interplay. The key insight that emerges is that the interaction...

Analyses of spatial or network data are now very common. Yet statistical inference is challenging since unobserved heterogeneity can be correlated across neighboring observational units. We develop an estimator for the variance-covariance matrix (VCV) of OLS and 2SLS that allows for arbitrary...

We analyze the optimal regional pattern of public employment in an information-constrained second-best redistribution policy showing that regionally differentiated public employment can serve as an expenditure side tagging device, bypassing or relaxing the equity-efficiency trade-off. The...

The paper uses a regional Computable General Equilibrium (CGE) model to analyse the effects of immigration on three small remote EU regions located within Scotland, Greece and Latvia. Two migration scenarios are assessed. In the first, total labour supply is affected. In the second, the...

We examine how interaction choices depend on the interplay of social and physical distance, and show that agents who are more central in the social network, or are located closer to the geographic center of interaction, choose higher levels of interactions in equilibrium. As a result, the level...

Multiple job holding rates differ substantially across U.S. regions, states, and metropolitan areas. Rates decrease markedly with respect to labor market size. These patterns have been largely overlooked, despite being relatively fixed over (at least) the 1998-2014 period. This paper explores...

An innovation which bypasses the need for instruments when estimating endogenous treatment effects is identification via conditional second moments. The most general of these approaches is Klein and Vella (2010) which models the conditional variances semiparametrically. While this is attractive,...

In this paper I investigate the causal returns to education for different educational groups in Germany by employing a new method by Klein and Vella (2010) that bases identification on the presence of conditional heteroskedasticity. Compared to IV methods, key advantages of this approach are...