Knowledge that Transforms

I am delighted to be able to present this lecture before so many people. I’m also very happy when I get to work with models inhabited by many people. That is the key to the framework for which Ed Prescott and I were cited by the Nobel Committee: Individuals are introduced explicitly in the models. Their decision problems are fully dynamic—they are forward looking. That is one of the prerequisites for what we ultimately seek, which is a framework we can use to evaluate economic policy. The eminent researcher and 1995 Nobel laureate in economics, Bob Lucas, from whom I have learned a great deal, wrote: “One of the functions of theoretical economics is to provide fully articulated, artificial economic systems that can serve as laboratories in which policies that would be prohibitively expensive to experiment with in actual economies can be tested out at much lower cost ... (Lucas, 1980, p. 696). Our task, as I see it ... is to write a FORTRAN program that will accept specific economic policy rules as ‘input’ and will generate as ‘output’ statistics describing the operating characteristics of time series we care about, which are predicted to result from these policies” (pp. 709–10). The desired environments to which Lucas refers would make use of information on “individual responses [that] can be documented relatively cheaply ... by means of ... censuses, panels [and] other surveys ...” (p. 710). Lucas seems to suggest that economic researchers place people in desired model environments and record how they behave under alternative policy rules. In practice, that is easier said than done. The key tool macroeconomists use is the computational experiment. With its help, the researcher performs exactly what I just described—places the model’s people in the desired environment and records their behavior. But the purpose of the computational experiment is broader than only to evaluate policy rules. The computational experiment is useful for answering a host of quantitative questions, that is, those for which we seek numerical answers. When evaluating government policy, the policy is stated in the form of a rule that specifies how the government will behave—what action to take under various contingencies—today and in the indefinite future. That is one reason it would be so difficult and prohibitively expensive to perform the alternative Lucas mentions, namely, to test the policies in actual economies.

The last two centuries have been characterized by dramatic changes in the distribution of income and population across the globe. While Western European economies have tripled their domination in terms of income per capita over Asian economies, significant resources in Asian countries have been channeled into to doubling their lead over Western Europe in the population dimension. This research argues that the rapid expansion of international trade in the second phase of the industrial revolution has played a major role in the timing of demographic transitions across countries and has thereby been a significant determinant of the distribution of world population and a prime cause of the ‘Great Divergence ’ in income levels across countries in the last two centuries. The analysis suggests that international trade had an asymmetrical effect on the evolution of industrial and non-industrial economies. While in the industrial nations the gains from trade were directed primarily towards investment in education and growth in output per capita, a significant portion of the gains from trade in non-industrial nations was channeled towards population growth. In the second phase of the Industrial Revolution, international trade enhanced the spe-cialization of industrial economies in the production of industrial, skilled intensive, goods. The associated rise in the demand for skilled labor induced an investment in the quality of the population, expediting a demographic transition, stimulating technological progress and fur-ther enhancing the comparative advantage of these industrial economies in the production of skilled intensive goods. In non-industrial economies, in contrast, international trade generated an incentive to specialize in the production of unskilled intensive, non-industrial, goods. The

This paper examines preferences toward particular classes of lottery pairs. We show how such concepts as prudence and temperance can be fully characterized by a preference relation over these lotteries. If preferences are defined in an expectedutility framework with differentiable utility, the direction of preference for a particular class of lottery pairs is equivalent to signing the n th derivative of the utility function. What makes our characterization appealing is its simplicity, which seems particularly amenable to experimentation.

Mixing across racial and ethnic lines could spur understanding or inflame tensions between groups. We find that white students at a large state university randomly assigned African American roommates in their first year were more likely to endorse affirmative action and view a diverse student body as essential for a high-quality education. They were also more likely to say they have more personal contact with, and interact more comfortably with, members of minority groups. Although sample sizes are too small to provide definitive evidence, these results suggest students become more empathetic with the social groups to which their roommates belong.

We analyze a model of participation in elections in which voting is costly and no vote is pivotal. Ethical agents are motivated to participate when they determine that agents of their type are obligated to do so. Unlike previous duty-based models of participation, in our model an ethical agent's obligation to vote is determined endogenously as a function of the behavior of other agents. Our model predicts high turnout and comparative statics that are consistent with strategic behavior.

We document that net equity issuance is considerably more sensitive to aggregate stock returns and Q's than to firm-level stock returns and Q's. Very similar patterns also emerge when we look at merger activity. In light of earlier work (Campbell 1991, Vuolteenaho 2002) which finds that aggregate stock returns are less informative about future cashflows than are firm-level stock returns--and thus, potentially more strongly influenced by investor sentiment--these results suggest that both equity issuance and mergers are to a significant extent driven by market-timing considerations, as opposed to by purely fundamental factors.

Nobel Prize Lecture, December 8, 2005

How should benefit-cost analysis account for the value that benevolent individuals place on others' enjoyment of public goods? When adding up the benefits to be compared with costs, should we sum the private valuations, the altruistic valuations, or something else? This paper argues that private valuations are appropriate if concern for the well-being of others respects their private preferences. The discussion has implications for family decision-making, welfare economics, and the design of applied contingent valuation studies.

The Caring Hand that Cripples: The East German Labor Market after Reunification by Dennis J. Snower and Christian Merkl. Published in volume 96, issue 2, pages 375-382 of American Economic Review, May 2006

We illustrate problems of measuring discrimination using elections to AEA offices. With a new econometric technique, we find female candidates have a much better than random chance of victory. This advantage is either reverse discrimination or reflects beliefs that women are more productive. The former interpretation could be explained by an unchanging median voter whose preferences were not satisfied by suppliers of candidates; but there was a structural change in voting behavior in the mid-1970s. The results suggest it is generally impossible to claim differences in rewards, for different groups measure the extent of discrimination or even its direction.