An Empirical Analysis of Racial Differences in Police Use of Force

This paper explores racial differences in police use of force. On non-lethal uses of force, blacks and Hispanics are more than fifty percent more likely to experience some form of force in interactions with police. Adding controls that account for important context and civilian behavior reduces, but cannot fully explain, these disparities. On the most extreme use of force – officer-involved shootings – we find no racial differences in either the raw data or when contextual factors are taken into account. We argue that the patterns in the data are consistent with a model in which police officers are utility maximizers, a fraction of which have a preference for discrimination, who incur relatively high expected costs of officer-involved shootings

Injecting Successful Charter School Strategies into Traditional Public Schools: A Field Experiment in Houston

We implemented five strategies gleaned from practices in achievement-increasing charter schools – increased instructional time, a more rigorous approach to building human capital of teachers and administrators, high-dosage tutoring, frequent use of data to inform instruction, and a culture of high expectations – in twenty of the lowest performing schools in Houston, Texas. We show that the average impact of these changes on student achievement is 0.206 standard deviations in math and 0.043 standard deviations in reading, per year, which is comparable to reported impacts of attending high-performing charter schools. This suggests that the best practices of charter schools may be general lessons about the education production function.

A Measure of Segregation Based on Social Interactions

We develop an index of segregation based on two premises: (1) a measure of segregation should disaggregate to the level of individuals, and (2) an individual is more segregated the more segregated are the agents with whom she interacts. We present an index that satisfies (1) and (2) and that is based on agents' social interactions: the extent to which blacks interact with blacks, whites with whites, etc. We use the index to measure school and residential segregation. Using detailed data on friendship networks, we calculate levels of within-school racial segregation in a sample of U. S. schools. We also calculate residential segregation across major U. S. cities, using block-level data from the 2000 U. S. Census

On the Measurement of Segregation

This paper develops a measure of segregation based on two premises: (1) a measure of segregation should disaggregate to the level of individuals, and (2) an individual is more segregated the more segregated are the agents with whom she interacts. Developing three desirable axioms that any segregation measure should satisfy, we prove that one and only one segregation index satisfies our three axioms, and the two aims mentioned above; which we coin the Spectral Segregation Index. We apply the index to two well-studied social phenomena: residential and school segregation. We calculate the extent of residential segregation across major US cities using data from the 2000 US Census. The correlation between the Spectral index and the commonly- used dissimilarity index is .42. Using detailed data on friendship networks, available in the National Longitudinal Study of Adolescent Health, we calculate the prevalence of within-school racial segregation. The results suggests that the percent of minority students within a school, commonly used as a substitute for a measure of in-school segregation, is a poor proxy for social interactions.segregation, networks, social interactions, school segregation, residential segregation

Getting Beneath the Veil of Effective Schools: Evidence from New York City

Charter schools were developed, in part, to serve as an R&D engine for traditional public schools, resulting in a wide variety of school strategies and outcomes. In this paper, we collect unparalleled data on the inner-workings of 35 charter schools and correlate these data with credible estimates of each school's effectiveness. We find that traditionally collected input measures -- class size, per pupil expenditure, the fraction of teachers with no certification, and the fraction of teachers with an advanced degree -- are not correlated with school effectiveness. In stark contrast, we show that an index of five policies suggested by over forty years of qualitative research -- frequent teacher feedback, the use of data to guide instruction, high-dosage tutoring, increased instructional time, and high expectations -- explains approximately 50 percent of the variation in school effectiveness. Our results are robust to controls for three alternative theories of schooling: a model emphasizing the provision of wrap-around services, a model focused on teacher selection and retention, and the "No Excuses'' model of education. We conclude by showing that our index provides similar results in a separate sample of charter schools.

An Empirical Analysis of 'Acting White'

There is a debate among social scientists regarding the existence of a peer externality commonly referred to as 'acting white.' Using a newly available data set (the National Longitudinal Study of Adolescent Health), which allows one to construct an objective measure of a student's popularity, we demonstrate that there are large racial differences in the relationship between popularity and academic achievement; our (albeit narrow) definition of 'acting white.' The effect is intensified among high achievers and in schools with more interracial contact, but non-existent among students in predominantly black schools or private schools. The patterns in the data appear most consistent with a two-audience signaling model in which investments in education are thought to be indicative of an individual's opportunity costs of peer group loyalty. Other models we consider, such as self-sabotage among black youth or the presence of an oppositional culture, all contradict the data in important ways.

Measuring the Compactness of Political Districting Plans

The United States Supreme Court has long recognized compactness as an important principle in assessing the constitutionality of political districting plans. We propose a measure of compactness based on the distance between voters within the same district relative to the minimum distance achievable -- which we coin the relative proximity index. We prove that any compactness measure which satisfies three desirable properties (anonymity of voters, efficient clustering, and invariance to scale, population density, and number of districts) ranks districting plans identically to our index. We then calculate the relative proximity index for the 106th Congress, requiring us to solve for each state's maximal compactness; an NP-hard problem. Using two properties of maximally compact districts, we prove they are power diagrams and develop an algorithm based on these insights. The correlation between our index and the commonly-used measures of dispersion and perimeter is -.22 and -.06, respectively. We conclude by estimating seat-vote curves under maximally compact districts for several large states. The fraction of additional seats a party obtains when their average vote increases is significantly greater under maximally compact districting plans, relative to the existing plans.

Multitasking, Learning, and Incentives: A Cautionary Tale

We develop a multi-period, multi-task principal-agent model in which neither the principal nor the agent knows the mapping from actions to outputs. The agent can learn about the production function over time by exerting effort and observing output. The model has a stark prediction: incentives may have a negative impact on agent effort if, by exerting effort, they learn their ability is lower than their prior beliefs. To provide evidence on the model’s predictions, we conduct a field experiment in fifty Houston public schools, where students, parents, and teachers were rewarded with financial incentives. The experimental data is consistent with the model’s most distinguishing predictions, though other explanations are possible.

Affirmative Action and Its Mythology

For more than three decades, critics and supporters of affirmative action have fought for the moral high ground ­ through ballot initiatives and lawsuits, in state legislatures, and in varied courts of public opinion. The goal of this paper is to show the clarifying power of economic reasoning to dispel some myths and misconceptions in the racial affirmative action debates. We enumerate seven commonly held (but mistaken) views one often encounters in the folklore about affirmative action (affirmative action may involve goals and timelines, but definitely not quotas, e.g.). Simple economic arguments reveal these seven views to be more myth than fact.

Categorical Cognition: A Psychological Model of Categories and Identification in Decision Making

There is a wealth of research in psychology demonstrating that agents process information with the aid of categories. In this paper we study this phenomenon in two parts. First, we build a model of how experiences are sorted into categories and how categorization affects decision making. Second, we analyze the personal biases that result from categorization, in economic contexts. We show that discrimination can result from such cognitive processes even when there is no malevolent taste to do so and workers' qualifications are fully observable. The model also provides a framework that is equipped to investigate the social psychological concept of identity, where identity is viewed as self-categorization.