Knowledge that Transforms

Residential segregation by race and income are enduring features of urban America. Understanding the effects of residential segregation on educational attainment, labor market outcomes, criminal activity, and other outcomes has been a leading project of the social sciences for over half a century. This paper describes techniques for measuring the effects of neighborhood of residence on long-run life outcomes.

The achievements and limitations of the classical theory of optimal labor-income taxation based on social welfare functions are now well known. Even though utilitarianism still dominates public economics, recent interest has arisen for broadening the normative approach and making room for fairness principles such as desert or responsibility. Fairness principles sometimes provide immediate recommendations about the relative weights to assign to various income ranges, but in general require a careful choice of utility representations embodying the relevant interpersonal comparisons. The main message of this paper is that the traditional tool of welfare economics, the social welfare function framework, is flexible enough to incorporate many approaches, from egalitarianism to libertarianism.

This paper reevaluates the basic prescriptions of monetary policy design in the new Keynesian paradigm through the lens of imperfect knowledge. We show that while the basic logic of monetary policy design under rational expectations continues to obtain, perfect knowledge and learning can limit the set of policies available to central banks, rendering expectations management in general more difficult. Nonetheless, the desirability of some form of price-level targeting, inducing inertia in interest-rate policy, paramount under rational expectations, is robust to the assumption of imperfect knowledge.

The pharmaceutical industry accounts for a substantial chunk of the US economy's research and development investments, which have resulted in significant medical breakthroughs. At the same time, the costs of pharmaceutical products continue to rise, as does pressure to adopt direct or indirect controls on pharmaceutical prices. We review the economics literature on the pharmaceutical industry, focusing particularly on its positive and normative implications for the innovation, pricing, and marketing decisions of pharmaceutical firms. We discuss the major achievements of, and persistent gaps in, the literature, along with lessons for policy.

In this paper, we survey the recent empirical literature on the effects of offshoring on wage, employment, and displacement. We start with an overview of the measurement of offshoring, organizing our discussion around the three key elements of offshoring: that it involves intermediate inputs for production (versus final goods for consumption); that it involves imported inputs (versus domestically produced ones); and that the inputs involved could have been produced internally within the same firm. We then briefly discuss the theories of offshoring and survey the literature that examines the wage effects of offshoring: the wave of studies using industry-level data; the wave using firm-level data; the wave using worker-level data; and the wave using matched worker-firm data. For each wave, we highlight the identification strategies used, critically assess its strengths and weaknesses, discuss its connections with theory, and draw out potential policy implications of its findings. Finally, we survey the literature that examines how offshoring affects employment and displacement. We highlight the recent development of a novel cohort-based approach that is specifically designed to address selection with displacement, and capable of identifying the overall effects of offshoring, including wage, displacement, and all other types of transitions.

This essay critically evaluates the analytic literature concerned with causal connections between Islam and economic performance. It focuses on works since 1997, when this literature was last surveyed comprehensively. Among the findings are the following: Ramadan fasting by pregnant women harms prenatal development; Islamic charities mainly benefit the middle class; Islam affects educational outcomes less through Islamic schooling than through structural factors that handicap learning as a whole; Islamic finance has a negligible effect on Muslim financial behavior; and low generalized trust depresses Muslim trade. The last feature reflects the Muslim world’s delay in transitioning from personal to impersonal exchange. The delay resulted from the persistent simplicity of the private enterprises formed under Islamic law. Weak property rights reinforced the private sector’s stagnation by driving capital from commerce to rigid waqfs. Waqfs limited economic development through their inflexibility and democratization by keeping civil society embryonic. Parts of the Muslim world conquered by Arab armies are especially undemocratic, which suggests that early Islamic institutions were particularly critical to the persistence of authoritarian patterns of governance. States have contributed to the persistence of authoritarianism by treating Islam as an instrument of governance. As the world started to industrialize, non-Muslim subjects of Muslim-governed states pulled ahead of their Muslim neighbors, partly by exercising the choice of law they enjoyed under Islamic law in favor of a Western legal system.

I describe and compare sources of data on citations in economics and the statistics derived from them. Constructing data sets of the post-publication citation histories of articles published in the “top five” journals in the 1970s and 2000s, I examine distributions and life cycles of citations, compare citation histories of articles in different subspecialties in economics, and present evidence on the history and heterogeneity of those journals' impacts and the marginal citation productivity of additional coauthors. I use a new data set of the lifetime citation histories of over 1,000 economists from thirty universities to rank economics departments by various measures and demonstrate the importance of intra- and interdepartmental heterogeneity in productivity. Throughout, the discussion summarizes earlier work, including the impacts of citations on salaries and nonmonetary rewards, and how citations reflect judgments about research quality in economics and the importance of economic ideas.

As normally measured, “global inequality” is the relative inequality of incomes found among all people in the world no matter where they live. Francois Bourguignon and Branko Milanovic have written insightful and timely books on global inequality, emphasizing the role of globalization. The books are complementary: Milanovic provides an ambitious broad-brush picture, with some intriguing hypotheses on the processes at work; Bourguignon provides a deep and suitably qualified economic analysis. This paper questions the thesis of both books—that globalization has been a major driving force of inequality between or within countries. The paper also questions the robustness of the evidence for declining global inequality, and notes some conceptual limitations of standard measures in capturing the concerns of many observers in the ongoing debates about globalization and the policy responses.

Research in international trade has changed dramatically over the last twenty years, as attention has shifted from countries and industries towards the firms actually engaged in international trade. The now-standard heterogeneous firm model posits measure-zero firms that compete under monopolistic competition and decide whether to export to foreign markets. However, much of international trade is dominated by a few “global firms,” which participate in the international economy along multiple margins and account for substantial shares of aggregate trade. We develop a new theoretical framework that allows firms to have large market shares and decide simultaneously on the set of production locations, export markets, input sources, products to export, and inputs to import. Using US firm and trade transactions data, we provide strong evidence in support of this framework's main predictions of interdependencies and complementarities between these margins of firm international participation. Global firms participate more intensively along each margin, magnifying the impact of underlying differences in firm characteristics and increasing their shares of aggregate trade.

A growing experimental literature studies the determinants of cooperation in infinitely repeated games, tests different predictions of the theory, and suggests an empirical solution to the problem of multiple equilibria. To provide a robust description of the literature's findings, we gather and analyze a metadata set of experiments on infinitely repeated prisoner's dilemma games. The experimental data show that cooperation is affected by infinite repetition and is more likely to arise when it can be supported in equilibrium. However, the fact that cooperation can be supported in equilibrium does not imply that most subjects will cooperate. High cooperation rates will emerge only when the parameters of the repeated game are such that cooperation is very robust to strategic uncertainty. We also review the results regarding the effect of imperfect monitoring, changing partners, and personal characteristics on cooperation and the strategies used to support it.