New Releases by Steven D Levitt

En esta obra, Levitt y Dubner demuestran, a través de ejemplos y una sarcástica perspicacia, que la economía representa el estudio de los incentivos. ¿Qué resulta más peligroso: una pistola o una piscina? ¿Qué tienen en común un maestro de escuela y un luchador de sumo? ¿Por qué continúan los traficantes de drogas viviendo con sus madres? ¿En qué se parecen el Ku Kux Klan a los agentes inmobiliarios? Quizás éstas no sean las típicas preguntas que se formula un experto en economía, pero Steven D. Levitt y Stephen J. Dubner no son unos economistas muy típicos. Se trata de especialistas que estudian la esencia y los enigmas de la vida cotidiana y cuyas conclusiones, con frecuencia, ponen patas arriba la sabiduría convencional. A través de ejemplos prácticos y de una sarcástica perspicacia, Levitt y Dubner demuestran que la economía, en el fondo, representa el estudio de los incentivos: el modo en que las personas obtienen lo que desean, o necesitan, especialmente cuando otras personas desean o necesitan lo mismo.

This study presents an overview of modern field experiments and their usage in economics. Our discussion focuses on three distinct periods of field experimentation that have influenced the economics literature. The first might well be thought of as the dawn of quot;fieldquot; experimentation: the work of Neyman and Fisher, who laid the experimental foundation in the 1920s and 1930s by conceptualizing randomization as an instrument to achieve identification via experimentation with agricultural plots. The second, the large-scale social experiments conducted by government agencies in the mid-twentieth century, moved the exploration from plots of land to groups of individuals. More recently, the nature and range of field experiments has expanded, with a diverse set of controlled experiments being completed outside of the typical laboratory environment. With this growth, the number and types of questions that can be explored using field experiments has grown tremendously. After discussing these three distinct phases, we speculate on the future of field experimental methods, a future that we envision including a strong collaborative effort with outside parties, most importantly private entities.

Agents are often better informed than the clients who hire them and may exploit this informational advantage. Real-estate agents, who know much more about the housing market than the typical homeowner, are one example. Because real estate agents receive only a small share of the incremental profit when a house sells for a higher value, there is an incentive for them to convince their clients to sell their houses too cheaply and too quickly. We test these predictions by comparing home sales in which real estate agents are hired by others to sell a home to instances in which a real estate agent sells his or her own home. In the former case, the agent has distorted incentives; in the latter case, the agent wants to pursue the first-best. Consistent with the theory, we find homes owned by real estate agents sell for about 3.7 percent more than other houses and stay on the market about 9.5 days longer, even after controlling for a wide range of housing characteristics. Situations in which the agent''s informational advantage is larger lead to even greater distortions.

The main results of the paper are as follows: Information in the National Crime Victimization Survey suggests that property crime victimization has become increasingly concentrated on the poor. For instance, in the mid-1970s households with incomes below $25,000 (in 1994 dollars) were actually burglarized slightly less than households with incomes greater than $50,000. By 1994, the poor households were 60 percent more likely to be burglarized than the rich households. For violent crime, however, a different pattern is observed. In the Chicago homicide data, homicide rates at a point in time are generally inversely related to median family income in the community. However, this relationship has substantially weakened over time for blacks and has disappeared completely for whites by 1990. This finding is particularly striking because cross-neighborhood income inequality increased substantially over the time period examined. In other words, the income gap between the richest and poorest communities grew substantially, but the murder gap shrunk.

Profit maximizing behavior on the part of firms is a fundamental, but rarely tested, assumption of economics. In this paper, I analyze the decisions made by an MIT trained economist running a company that delivers bagels and donuts. The simplicity and transparency of the business (e.g. marginal cost is easily observed) allow for direct tests of profit maximization in the quantities delivered each day and the prices that are charged. Using thirteen years of data representing more than 80,000 deliveries, I find that the company is extremely adept at determining how many bagels and donuts to deliver to a particular customer on a given day. In stark contrast, the company appears to price on the inelastic portion of the demand curve for the entire period, thereby foregoing a substantial share of available profits. I argue that these results generalize well beyond this particular case study: firms are likely to be close to the efficient frontier on dimensions for which there is frequent and informative feedback regarding profits, but absent that feedback, systematic deviations from profit maximization are more likely.

In most settings, it is difficult to measure discrimination, and even more challenging to distinguish between competing theories of discrimination (taste-based versus information-based). Using contestant voting behavior on the television game show Weakest Link, one can in principle empirically address both of these questions. On the show, contestants answer questions and vote off other players, competing for a winner-take-all prize. In early rounds, strategic incentives encourage voting for the weakest competitors. In later rounds, the incentives reverse, and the strongest competitors become the logical target. Controlling for other observable characteristics including the number of correct answers thus far, both theories of discrimination predict that in early rounds, excess votes will be made against groups targeted for discrimination. In later rounds, however, taste-based models predict continued excess votes, whereas statistical discrimination predicts fewer votes against the target group. Empirically, I find some evidence of information-based discrimination towards Hispanics (i.e., other players perceive them as having low ability) and taste-based discrimination against older players (i.e., other players treat them with animus). There is little in the data to suggest discrimination against women and Blacks

Although the theoretical literature on corruption is well developed, empirical work in this area has lagged because it has proven difficult to isolate corrupt behavior in the data. In this paper, we look for evidence of corruption in an unlikely place: the highest echelons of Japanese sumo wrestling. This paper provides strong statistical evidence documenting match rigging in sumo wrestling. A non-linearity in the incentive structure of promotion leads to gains from trade between wrestlers on the margin for achieving a winning record and their opponents. We show that wrestlers win a disproportionate share of the matches when they are on the margin. Increased effort can not explain the findings. Winning on the bubble is more frequent when the two competitors have met often in the past. Success on the bubble tends to rise over the course of a wrestler''s career, but declines in his last year, consistent with the game theoretic predictions. Wrestlers who are victorious when on the bubble lose more frequently than would be expected the next time they meet that opponent, suggesting that part of the payment for throwing a match is future payment in kind. Systematic differences across wrestling stables suggest that the stables play a role in facilitating the corruption. In times of increased media scrutiny, the match rigging disappears.

Over the last two decades the punitiveness of the juvenile justice system has declined" substantially relative to the adult courts. During that same time period juvenile violent crime" rates have grown almost twice as quickly as adult crime rates. This paper examines the degree to" which those two empirical observations are related, finding that changes in relative punishments" can account for 60 percent of the differential growth rates in juvenile and adult violent crime" between 1978 and 1993. Juvenile offenders appear to be at least as responsive to criminal" sanctions as adults. Moreover, sharp changes in criminal involvement with the transition from" the juvenile to the adult court suggest that deterrence, rather than simply incapacitation important role. There does not, however, appear to be a strong relationship between the" punitiveness of the juvenile justice system that a cohort faces and the extent of criminal" involvement for that cohort later in life.