Paul M. Romer

Endogenous Technological Change

Growth in this model is driven by technological change that arises from intentional investment decisions made by profit-maximizing agents. The distinguishing feature of the technology as an input is that it is neither a conventional good nor a public good; it is a nonrival, partially excludable good. Because of the nonconvexity introduced by a nonrival good, price-taking competition cannot be supported. Instead, the equilibrium is one with monopolistic competition. The main conclusions are that the stock of human capital determines the rate of growth, that too little human capital is devoted to research in equilibrium, that integration into world markets will increase growth rates, and that having a large population is not sufficient to generate growth.

Increasing Returns and Long-Run Growth

This paper presents a fully specified model of long-run growth in which knowledge is assumed to be an input in production that has increasing marginal productivity. It is essentially a competitive equilibrium model with endogenous technological change. In contrast to models based on diminishing returns, growth rates can be increasing over time, the effects of small disturbances can be amplified by the actions of private agents, and large countries may always grow faster than small countries. Long-run evidence is offered in support of the empirical relevance of these possibilities.

Economic Integration and Endogenous Growth

In a world with two similar, developed economies, economic integration can cause a permanent increase in the worldwide rate of growth. Starting from a position of isolation, closer integration can be achieved by increasing trade in goods or by increasing flows of ideas. We consider two models with different specifications of the research and development sector that is the source of growth. Either form of integration can increase the long-run rate of growth if it encourages the worldwide exploitation of increasing returns to scale in the research and development sector.

Idea gaps and object gaps in economic development

Abstract A nation that lacks physical objects like factories and roads suffers from an object gap. A nation that lacks the knowledge used to create value in a modern economy suffers from an idea gap. Object gaps are emphasized by mainstream economists who make use of formal models and statistical hypothesis tests. Idea gaps are emphasized by dissident economists who make use of a diverse body of evidence and avoid formal models. Economists need to use the formal models from the first approach and the diverse evidence from the second to fully appreciate the importance of idea gaps in economic development.

New Goods, Old Theory, and the Welfare Costs of Trade Restrictions

The typical economic model implicitly assumes that the set of goods in an economy never changes. As a result, the predicted efficiency loss from a tariff is small, on the order of the square of the tariff rate. If we loosen this assumption and assume that international trade can bring new goods into an economy, the fraction of national income lost when a tariff is imposed can be much larger, as much as two times the tariff rate. Much of this paper is devoted to explaining why this seemingly small change in the assumptions of a model can have such important positive and normative implications. The paper also asks why the implications of new goods have not been more extensively explored, especially given that the basic economic issues were identified more than 150 years ago. The mathematical difficulty of modeling new goods has no doubt been part of the problem. An equally, if not more important stumbling block has been the deep philosophical resistance that humans feel toward the unavoidable logical consequence of assuming that genuinely new things can happen at every juncture: the world as we know it is the result of a long string of chance outcomes.

Looting: The Economic Underworld of Bankruptcy for Profit

During the 1980s, a number of unusual financial crises occurred. In Chile, for example, the financial sector collapsed, leaving the government with responsibility for extensive foreign debts. In the United States, large numbers of government-insured savings and loans became insolvent - and the government picked up the tab. In Dallas, Texas, real estate prices and construction continued to boom even after vacancies had skyrocketed, and the suffered a dramatic collapse. Also in the United States, the junk bond market, which fueled the takeover wave, had a similar boom and bust. In this paper, we use simple theory and direct evidence to highlight a common thread that runs through these four episodes. The theory suggests that this common thread may be relevant to other cases in which countries took on excessive foreign debt, governments had to bail out insolvent financial institutions, real estate prices increased dramatically and then fell, or new financial markets experienced a boom and bust. We describe the evidence, however, only for the cases of financial crisis in Chile, the thrift crisis in the United States, Dallas real estate and thrifts, and junk bonds. Our theoretical analysis shows that an economic underground can come to life if firms have an incentive to go broke for profit at societys expense (to loot) instead of to go for broke (to gamble on success). Bankruptcy for profit will occur if poor accounting, lax regulation, or low penalties for abuse give owners an incentive to pay themselves more than their firms are worth and then default on their debt obligations.

International trade with endogenous technological change

To explain why trade restrictions sometimes speed up worldwide growth and sometimes slow it down, we exploit an analogy with the theory of consumer behavior. substitution effects make demand curves slope down, but income effects can increase or decrease the slope, and can sometimes overwhelm the substitution effect. We decompose changes in the worldwide growth rate into two effects (integration and redundancy) that unambiguously slow down growth, and a third effect (allocation) that can either speed it up or slow it down. We study two types of trade restrictions to illustrate the use of this decomposition. The first is across the board restrictions on traded goods in an otherwise perfect market. The second is selective protection of knowledge-intensive goods in a world with imperfect intellectual property rights. In both examples, we show that for trade between similar regions such as Europe and North America, the first two effects dominate; starting from free trade, restrictions unambiguously reduce worldwide growth.

Crazy Explanations for the Productivity Slowdown

This article argues that to understand the behavior of productivity statistics, it is necessary to reexamine the basic assumptions underlying growth accounting. In particular, it offers theoretical and empirical support for the assertion that the elasticity of output with respect to an input like capital or labor might differ from the share of the input in total factor income. The theories offered in support of this possibility allow for spillovers of knowledge, specialization with monopolistic competition, and endogenous accumulation of labor-saving technological change. Evidence on the form of aggregate production is drawn from data for many countries and for long historical time periods. The specific interpretation of the productivity slowdown that is offered is that a low elasticity of output with respect to labor causes labor productivity growth rates to fall when labor growth speeds up.

Capital, Labor, and Productivity

No abstract is available for this paper.

Should the Government Subsidize Supply or Demand in the Market for Scientists and Engineers

This paper suggests that innovation policy in the United States has erred by subsidizing the private sector demand for scientists and engineers without asking whether the educational system provides the supply response necessary for these subsidies to work. It suggests that the existing institutional arrangements in higher education limit this supply response. To illustrate the path not taken, the paper considers specific programs that could increase the numbers of scientists and engineers available to the private sector.