Gene M. Grossman

Quality Ladders in the Theory of Growth

We develop a model of repeated product improvements in a continuum of sectors. Each product follows a stochastic progression up a quality ladder. Progress is not uniform across sectors, so an equilibrium distribution of qualities evolves over time. But the rate of aggregate growth is constant. The growth rate responds to profit incentives in the R&D sector. We explore the welfare properties of our model. Then we relate our approach to an alternative one that views product innovation as a process of generating an ever-expanding range of horizontally differentiated products. Finally, we apply the model to issues of resource accumulation and international trade.

Integration versus Outsourcing in Industry Equilibrium

We develop an equilibrium model of industrial structure in which the organization of firms is endogenous. Differentiated consumer products can be produced either by vertically integrated firms or by pairs of specialized companies. Production of each variety of consumer good requires a unique, specialized component. Vertically integrated firms can manufacture the components they need in the quantity and type that maximizes profits, but they face a relatively high cost due to diseconomies of scope. Specialized firms can produce at lower cost, but outsourcing imposes costs due to search frictions and imperfect contracting. We study the equilibrium mode of organization when inputs are fully or partially specialized. We consider how the degree of competition in the industry, the nature of the search technology, the division of bargaining strength between intermediate and final producers, and the sensitivity of manufacturing costs to input characteristics affect the equilibrium organizational form.

Electoral Competition and Special Interest Politics

We study the competition between two political parties for seats in a parliament. The parliament will set two types of policies: ideological and non-ideological. The parties have fixed positions on the ideological issues, but choose their non-ideological platforms to attract voters and campaign contributions. In this context, we ask: How do the equilibrium contributions from special interest groups influence the platforms of the parties? We show that each party is induced to behave as if it were maximizing a weighted sum of the aggregate welfares of informed voters and members of special interest groups. The party that is expected to win a majority of seats caters more to the special interests.

Quality Ladders and Product Cycles

We develop a two-country model of endogenous innovation and imitation in order to study the interactions between these two processes. Firms in the North race to bring out the next generation of a set of technology-intensive products. Each product potentially can be improved a countably infinite number of times, but quality improvements require the investment of resources and entail uncertain prospects of success. In the South, entrepreneurs invest resources in order to learn the production processes that have been developed in the North. All R&D investment decisions are made by forward looking, profit maximizing entrepreneurs. The steady-state equilibrium is characterized by constant aggregate rates of innovation and imitation. We study how these rates respond to changes in the sizes of the two regions and to policies in each region to promote learning.

Endogenous Product Cycles

We construct a model of the product cycle featuring endogenous innovation and endogenous technology transfer. Competitive entrepreneurs in the North expend resources to bring out new products whenever expected present discounted value of future oligopoly profits exceeds current product development costs. Each Northern oligopolist continuously faces the risk that its product will be copied by a Southern imitator, at which time its profit stream will come to an end. In the South, competitive entrepreneurs may devote resources to learning the production processes that have been developed in the North. There too, costs (of reverse engineering) must be covered by a stream of operating profits. We study the determinants of the long-run rate of growth of the world economy, and the long-run rate of technological diffusion. We also provide an analysis of the effects of exogenous events and of public policy on relative wage rates in the two regions.

Product Development and International Trade

We develop a multicountry, dynamic general equilibrium model of product innovation and international trade to study the creation of comparative advantage through research and development and the evolution of world trade over time. In our model, firms must incur resource costs to introduce new products, and forward-looking potential producers conduct R & D and enter the product market whenever profit opportunities exist. Trade has both intraindustry and interindustry components, and the different incentives that face agents in different countries for investment and savings decisions give rise to intertemporal trade. We derive results on the dynamics of trade patterns and trade volume and on the temporal emergence of multinational corporations.

Income Distribution, Product Quality, and International Trade

We develop a framework for studying trade in horizontally and vertically differentiated products. In our model, consumers with heterogeneous incomes and tastes purchase a homogeneous good and make a discrete choice of quality and variety of a differentiated product. The distribution of preferences generates a nested-logit demand structure such that the fraction of consumers who buy a higher-quality product rises with income. The model features a home-market effect that helps to explain why richer countries export higher-quality goods. It provides a tractable tool for studying the welfare consequences of trade and trade policy for different income groups in an economy.

Pollution and Growth: What Do We Know?

This paper reviews the empirical evidence on the relationship between economic output and various dimensions of air and water quality. Pollution may rise with growth, because an increased scale of economic activity means more emissions, ceteris paribus. Economic growth may be associated with a change in the composition of economic output, however, or in the techniques that are used in production. In the event, growth may lead to an alleviation of some forms of environmental problems. We find that not all measures of environmental quality have been similarly affected by increases in output. Along some dimensions, conditions have improved monotonically with increases in per capita output and the associated rises in standards of material living. For other pollutants there is an inverted-u shaped relationship with output. Finally, for some types of pollution there is no evidence at all that a turning point has yet been reached. The paper goes on to discuss the economic factors that determine the likely pattern for different types of pollutants and the implications of the findings for environmental policy.

Diversity and Trade

We develop a competitive model of trade between countries with similar aggregate factor endowments. The trade pattern reflects differences in the distribution of talent across the labor forces of the two countries. The country with a relatively homogenous population exports the good produced by a technology with complementarities between tasks. The country with a more diverse work force exports the good for which individual success is more important. Imperfect observabilitiy of talent strengthens the forces of comparative advantage. Finally, we examine an aspect of education policy concerning the spread of human capital across the student population.

Targeted Export Promotion with Several Oligopolistic Industries

In this paper we ask whether a policy of targeted export promotion can raise domestic welfare when several oligopolistic industries all draw on the same scarce factor of production. Our point of departure is one of Cournot duopoly in which a single home firm competes with a single foreign firm in a market outside the horse country. It has been shown previously that when there is only one such industry in an otherwise perfectly competitive world economy, a subsidy policy by the home government transfers profits to the domestic firm, and thereby raises domestic welfare. However,when many such industries (and only these) utilize the same inelastically supplied resource, promotion of one bids up the return to the specific factor, and consequently disadvantages all of the non-targeted industries in their respective duopolistic competitions. Our question then is which industry(s), if any, is worthy of promotion. We find that, when the specific factor is used in fixed proportion to output, and all of the duopolies have similar demand and cost conditions, a policy of free trade is optimal. We identify the conditions for welfare improvement when a single industry is selected for targeting under asymmetric conditions, and also investigate whether a uniform subsidy to all industries in the imperfectly competitive sector will raise domestic welfare.