Using a new nationally representative dataset, we find minor differences in test outcomes between black and white infants that disappear with a limited set of controls. However, relative to whites, all other races lose substantial ground by age two. Combining our estimates with results in prior literature, we show that a simple model with assortative mating fits our data well, implying that differences in children's environments between racial groups can fully explain gaps in intelligence. If parental ability influences a child's test scores both genetically and through environment, then our findings are less informative and can be reconciled with a wide range of racial differences in inherited intelligence.

The minimax argument represents game theory in its most elegant form: simple but with stark predictions. Although some of these predictions have been met with reasonable success in the field, experimental data have generally not provided results close to the theoretical predictions. In a striking study, Palacios-Huerta and Volij ( 2008) presented evidence that potentially resolves this puzzle: both amateur and professional soccer players play nearly exact minimax strategies in laboratory experiments. In this paper, we establish important bounds on these results by examining the behavior of four distinct subject pools: college students, bridge professionals, world-class poker players, who have vast experience with high-stakes randomization in card games, and American professional soccer players. In contrast to Palacios-Huerta and Volij's results, we find little evidence that real-world experience transfers to the lab in these games-indeed, similar to previous experimental results, all four subject pools provide choices that are generally not close to minimax predictions. We use two additional pieces of evidence to explore why professionals do not perform well in the lab: (i) complementary experimental treatments that pit professionals against preprogrammed computers and (ii) post-experiment questionnaires. The most likely explanation is that these professionals are unable to transfer their skills at randomization from the familiar context of the field to the unfamiliar context of the lab. Copyright 2010 The Econometric Society.

Each year, more than 250 students in the Chicago Public Schools (CPS) are shot. The authors of this paper worked with the leadership of CPS to build a predictive model of shootings that helped determine which students would be included in a highly targeted and resource intensive mentorship program. This paper describes our predictive model and offers a preliminary evaluation of the mentoring intervention performed by Youth Advocate Programs, Inc. (YAP). We find little evidence that the intervention reduces school misconducts or improves educational outcomes. The scale of intervention was too small to generate meaningful findings on shootings.

Although backward induction is a cornerstone of game theory, most laboratory experiments have found that agents are not able to successfully backward induct. We analyze the play of world-class chess players in the centipede game, which is ill-suited for testing backward induction, and in pure backward induction games—Race to 100 games. We find that chess players almost never play the backward induction equilibrium in the centipede game, but many properly backward induct in the Race to 100 games. We find no systematic within-subject relationship between choices in the centipede game and performance in pure backward induction games. (JEL C73)

School choice has become an increasingly prominent strategy for enhancing academic achievement. To evaluate the impact on participants, we exploit randomized lotteries that determine high school admission in the Chicago Public Schools. Compared to those students who lose lotteries, students who win attend high schools that are better in a number of dimensions, including peer achievement and attainment levels. Nonetheless, we find little evidence that winning a lottery provides any systematic benefit across a wide variety of traditional academic measures. Lottery winners do, however, experience improvements on a subset of nontraditional outcome measures, such as self-reported disciplinary incidents and arrest rates.

What Does Performance in Graduate School Predict? Graduate Economics Education and Student Outcomes by Susan Athey, Lawrence F. Katz, Alan B. Krueger, Steven Levitt and James Poterba. Published in volume 97, issue 2, pages 512-520 of American Economic Review, May 2007

We investigate learning by doing using detailed data from a major auto producer’s assembly plant. We focus on the acquisition, aggregation, transmission, and embodiment of the knowledge stock built through learning. We find that most knowledge was not retained by plant workers despite their importance as a learning conduit. This is consistent with the plant’s systems for productivity measurement and improvement. We further explore how learning at the hundreds of processes along the production line undergirds plantwide productivity. Our results shed light on how productivity gains accrue at the plant level and how firms apply managerial inputs to expand production.

Exploring the Impact of Financial Incentives on Stereotype Threat: Evidence from a Pilot Study by Roland G. Fryer Jr., Steven D. Levitt and John A. List. Published in volume 98, issue 2, pages 370-75 of American Economic Review, May 2008

Since 1970, the fraction of mixed-race black-white births has increased nearly ninefold. This paper describes basic facts about the behaviors and outcomes of black-white mixed-race individuals. Unsurprisingly, on a host of background and achievement characteristics, as well as adult outcomes, mixed-race individuals fall in between whites and blacks. When it comes to engaging in risky and antisocial adolescent behavior, however, mixed-race adolescents are stark outliers compared to both blacks and whites. We argue that these behavioral patterns are most consistent with a two-sector Roy model, in which mixed-race adolescents, not having a predetermined peer group, engage in more risky behaviors in order to be accepted.