Person:

Helpman, Elhanan

We introduce firm and worker heterogeneity into a model of innovation-driven endogenous growth. Individuals who differ in ability sort into either a research sector or a manufacturing sector that produces differentiated goods. Each research project generates a new variety of the differentiated product and a random technology for producing it. Technologies differ in complexity and productivity, and technological sophistication is complementary to worker ability. We study the co-determination of growth and income inequality in both the closed and open economy, as well as the spillover effects of policy and conditions in one country to outcomes in others.

Recent theories of firm heterogeneity emphasize between-firm wage differences as a new mechanism through which trade can affect wage inequality. Using linked employer-employee data for Sweden, we show that many of the stylized facts about wage inequality found in Helpman et al. (2012) for Brazil also hold for Sweden. Much of overall wage inequality arises within sector-occupations and for workers with similar observable characteristics. One notable difference is a smaller contribution from between-firm differences in wages in Sweden, which could reflect the influence of Swedish labor market institutions in dampening the scope for variation in wages between firms through collective wage agreements.

We develop a framework for studying trade in vertically and horizontally differentiated products. In our model, consumers with heterogeneous incomes and tastes purchase a homogeneous good as well as making a discrete choice of quality and variety of a differentiated product. The distribution of preferences in the population generates a nested logit demand structure. These demands are such that the fraction of consumers who buy a higher-quality product rises with income. We use the model to study the pattern of trade between countries that differ in size and income distributions but are otherwise identical. Trade―which is driven primarily by demand factors―derives from "home market effects" in the presence of transport costs. The model helps to explain why richer countries export higher-quality goods. It provides a tractable tool for studying the welfare consequences of trade, transport costs, and trade policy for different income groups in an economy.

This paper develops a new framework for examining the determinants of wage distributions that emphasizes within-industry reallocation, labor market frictions, and differences in workforce composition across firms. More productive firms pay higher wages and exporting increases the wage paid by a firm with a given productivity. The opening of trade enhances wage inequality and can either raise or reduce unemployment. While wage inequality is higher in a trade equilibrium than in autarky, gradual trade liberalization first increases and later decreases inequality.

We study a two-country two-sector model of international trade in which one sector produces homogeneous products while the other produces differentiated products. The differentiated-product industry has firm heterogeneity, monopolistic competition, search and matching in its labor market, and wage bargaining. Some of the workers searching for jobs end up being unemployed. Countries are similar except for frictions in their labor markets. We study the interaction of labor market rigidities and trade impediments in shaping welfare, trade flows, productivity, price levels and unemployment rates. We show that both countries gain from trade but that the flexible country -- which has lower labor market frictions -- gains proportionately more. A flexible labor market confers comparative advantage; the flexible country exports differentiated products on net. A country benefits by lowering frictions in its labor market, but this harms the country's trade partner. And the simultaneous proportional lowering of labor market frictions in both countries benefits both of them. The model generates rich patterns of unemployment. Specifically, trade integration -- which benefits both countries -- may raise their rates of unemployment. Moreover, differences in rates of unemployment do not necessarily reflect differences in labor market rigidities; the rate of unemployment can be higher or lower in the flexible country. Finally, we show that the flexible country has both higher total factor productivity and a lower price level, which operates against the standard Balassa-Samuelson effect.

We study the determinants of the location of sub-contracted activity in a general equilibrium model of outsourcing and trade. We model outsourcing as an activity that requires search for a partner and relationship-specific investments that are governed by incomplete contracts. The extent of international outsourcing depends inter alia on the thickness of the domestic and foreign market for input suppliers, the relative cost of searching in each market, the relative cost of customizing inputs, and the nature of the contracting environment in each country.

We examine the protective effect of a tariff in a small economy with uncertainty and a stock market in which shares of firms are traded. In a deterministic economy, the allocation of resources is governed by commodity prices; in our economy, it is governed by equity prices and is dependent on commodity prices only to the extent that they influence equity prices. We show that in the absence of international trade in securities a tariff need not protect the import competing sector. In the presence of international trade in securities, a tariff always protects the import competing sector.

Whether governments clash in trade disputes or negotiate over trade agreements, their actions in the international arena reflect political conditions back home. Previous studies of cooperative and non-cooperative trade relations have focused on governments that are immune from political pressures and act as benevolent servants of the public interest. Here we take a first step towards introducing domestic politics into the analysis of international economic relations. We study the interactions between national leaders who are concerned both with providing a high standard of living to the general electorate and collecting campaign contributions from special interest groups. The analysis reveals the determinants of the structure of protection in a non-cooperative trade war and in a cooperative trade agreement.

We develop a model of common agency with complete information and general preferences with nontransferable utility, and we prove that the principals' Nash equilibrium in truthful strategies implements an efficient action. We apply this theory to the construction of a positive model of public finance, where organized special interests can lobby the government for consumer and producer taxes or subsidies and targeted lump‐sum taxes or transfers. The lobbies use only the nondistorting transfers in their noncooperative equilibrium, but their intergroup competition for transfers turns into a prisoners' dilemma in which the government captures all the gain that is potentially available to the parties.

We develop a tractable framework for the analysis of the relationship between contractual incompleteness, technological complementarities, and technology adoption. In our model, a firm chooses its technology and investment levels in contractible activities by suppliers of intermediate inputs. Suppliers then choose investments in noncontractible activities, anticipating payoffs from an ex post bargaining game. We show that greater contractual incompleteness leads to the adoption of less advanced technologies, and that the impact of contractual incompleteness is more pronounced when there is greater complementary among the intermediate inputs. We study a number of applications of the main framework and show that the mechanism proposed in the paper can generate sizable productivity differences across countries with different contracting institutions, and that differences in contracting institutions lead to endogenous comparative advantage differences.