This paper describes a range of methods which have been proposed to study interactions in economic and social contexts. By interactions, we refer to interdependences between individual decisions which are not mediated by markets. These types of models have been employed to understand phenomena...

The standard revealed-preference approach to welfare economics encounters fundamental difficulties when the act of choosing directly affects welfare through emotions such as guilt, pride, and anxiety. We address this problem by developing an approach that redefines consumption bundles in terms...

Empirical evidence suggests that individuals often evaluate options relative to a reference point, especially seeking to avoid losses. We undertake the first welfare analysis under reference-dependent preferences. We characterize the welfare impact of changes in reference points and prices,...

Using a new survey, we show that the dispersion of marginal products across firms in the European Union is about twice as large as that in the United States. Reducing it to the US level would increase EU GDP by more than 30 percent. Alternatively, removing barriers between industries and...

We study optimal transport networks in spatial equilibrium. We develop a framework consisting of a neoclassical trade model with labor mobility in which locations are arranged on a graph. Goods must be shipped through linked locations, and transport costs depend on congestion and on the...

We examine the relationship between immigration and attitudes toward redistribution using a newly assembled data set of immigrant stocks for 140 regions of 16 Western European countries. Exploiting within-country variations in the share of immigrants at the regional level, we find that native...

This paper explores a series of general-equilibrium models in which people can choose to be either producers or predators, and in which producers can allocate their resources either to production or to guarding their production against predators. The analysis shows how the ratio of predators to...

Changes in government spending often lead to significant shifts in demand across sectors. This paper analyzes the effects of sector-specific changes in government spending in a two-sector dynamic general equilibrium model in which the reallocation of capital across sectors is costly. The...