The equilibrium relationship between trade and the spatial distribution of economic activity is fundamental to the analysis of national and regional trade patterns, as well as to the effect of trade frictions. We study this relationship using a trade model with a continuum of regions, transport costs, and agglomeration effects caused by production externalities. We analyze the equilibrium specialization and trade patterns for different levels of transport costs and externality parameters. Understanding trade via the distribution of economic activity in space naturally rationalizes the evidence on border effects and the “gravity equation.”

We present an equilibrium theory of the organization of work in an economy where knowledge is an essential input in production and agents are heterogeneous in skill. Agents organize production by matching with others in knowledge hierarchies designed to use and communicate their knowledge efficiently. Relative to autarky, organization leads to larger cross-sectional differences in knowledge and wages: low skill workers learn and earn relatively less. We show that improvements in the technology to acquire knowledge lead to opposite implications on wage inequality and organization than reductions in communication costs.

The location of individuals determines their job and schooling opportunities, amenities, and housing costs. We conceptualize the location choice of individuals as a decision to invest in a “location asset.” This asset has a current cost equal to the location's rent, and a future payoff through better job and schooling opportunities. As with any asset, savers in the location asset transfer resources into the future by going to expensive locations with high future returns. In contrast, borrowers transfer resources to the present by going to cheap locations that offer few other advantages. Holdings of the location asset depend on its comparison to other assets, with the distinction that the location asset is not subject to borrowing constraints. We propose a dynamic location model and derive an agent's mobility choices after experiencing income shocks. We document the investment dimension of location and confirm the core predictions of our theory using French individual panel data from tax returns.

Since the seminal work of Lawrence F. Katz and Kevin M. Murphy (1992), the study of wage inequality has taken as its starting point a neoclassical constant-elasticity-of-substitution production function using as inputs capital and lowand high-skill labor. This approach assumes that the organization of production is fixed and determined by a particular specification of technology, and it ignores both the source of the interaction between workers and the organizational aspects of this interaction. These shortcomings are particularly important in light of growing empirical evidence that points, first, to the importance of decreases in the cost of processing and communicating information and, second, to the complementarity between organizational change and adjustments in the distribution of wages (e.g., Timothy F. Bresnahan et al., 2002). This paper argues that theories that seek to guide empirical research on these areas must put knowledge and information at the center of the analysis of organizations and link the organizational structure with aggregate variables via equilibrium frameworks. In Garicano and Rossi-Hansberg (2003), we present a model of this kind. It determines the patterns of organization, as manifested by the communication and specialization patterns, and the implied wage structure, that result from different costs of acquiring and communicating information. Here, we present a simple variant of this theory that allows us to focus on one of the main aspects of that framework: the sorting of agents into teams and the wage and organizational structure that accompanies that sorting. We use this simple model to analyze the changes in organization and wages that result from a very specific type of technological change: a reduction in the cost of communicating knowledge or information. This model allows us to consider the effect on within-class wage inequality, and the impact of information technology on the creation and form of organizations (e.g., size distribution of hierarchies). However, because knowledge is exogenously given, and agents cannot invest in learning, an important margin of the model in Garicano and Rossi-Hansberg (2003) is fixed, namely, the degree of “decentralization” or the extent to which problems are solved at lower levels. That model allows the simultaneous study of the acquisition of knowledge, spans of control, and matching in equilibrium. Moreover, it goes beyond the current analysis in that it allows for organizations with an unconstrained number of layers, and in that it studies two aspects of the impact of information technology: communication technology (like here) and the technology to acquire knowledge or information (e.g., processing power through cheaper database access).

We study a world with national external economies of scale at the industry level. In contrast to the standard treatment with perfect competition and two industries, we assume Bertrand competition in a continuum of industries. With Bertrand competition, each firm can internalize the externalities from production by setting a price below those set by others. This out-of-equilibrium threat eliminates many of the “pathologies” of the standard treatment. There typically exists a unique equilibrium with trade guided by “natural” comparative advantage. And, when a country has CES preferences and any finite elasticity of substitution between goods, gains from trade are ensured.

We propose a theory of task trade between countries that have similar relative factor endowments and technological capabilities, but may differ in size. Firms produce differentiated goods by performing a continuum of tasks, each of which generates local spillovers. Tasks can be performed at home or abroad, but offshoring entails costs that vary by task. In equilibrium, the tasks with the highest offshoring costs may not be traded. Among the remainder, those with the relatively higher offshoring costs are performed in the country that has the higher wage and the higher aggregate output. We discuss the relationship between equilibrium wages, equilibrium outputs, and relative country size.

We prove the existence of a symmetric equilibrium in a circular city in which businesses and housing can both be located anywhere in the city. In this equilibrium, firms balance the external benefits from locating near other producers against the costs of longer commutes for workers. An equilibrium city need not take the form of a central business district surrounded by a residential area. We propose a general algorithm for constructing equilibria, and use it to study the way land use is affected by changes in the model's underlying parameters. Copyright The Econometric Society 2002.

We propose a theory of the global production process that focuses on tradeable tasks, and use it to study how falling costs of offshoring affect factor prices in the source country. We identify a productivity effect of task trade that benefits the factor whose tasks are more easily moved offshore. In the light of this effect, reductions in the cost of trading tasks can generate shared gains for all domestic factors, in contrast to the distributional conflict that typically results from reductions in the cost of trading goods.

Most economic activity occurs in cities. This creates a tension between local increasing returns, implied by the existence of cities, and aggregate constant returns, implied by balanced growth. To address this tension, we develop a general equilibrium theory of economic growth in an urban environment. In our theory, variation in the urban structure through the growth, birth, and death of cities is the margin that eliminates local increasing returns to yield constant returns to scale in the aggregate. We show that, consistent with the data, the theory produces a city size distribution that is well approximated by Zipf's law, but that also displays the observed systematic underrepresentation of both very small and very large cities. Using our model, we show that the dispersion of city sizes is consistent with the dispersion of productivity shocks found in the data.

How does the formation of cross-country teams affect the organization of work and the structure of wages? To study this question, we propose a theory of the assignment of heterogeneous agents into hierarchical teams, where less skilled agents specialize in production and more skilled agents specialize in problem solving. We first analyze the properties of the competitive equilibrium of the model in a closed economy, and show that the model has a unique and efficient solution. We then study the equilibrium of a two-country model (North and South), where countries differ in their distributions of ability, and in which agents in different countries can join together in teams. We refer to this type of integration as globalization. Globalization leads to better matches for all southern workers but only for the best northern workers. As a result, we show that globalization increases wage inequality among nonmanagers in the South, but not necessarily in the North. We also study how globalization affects the size distribution of firms and the patterns of consumption and trade in the global economy.