Racial Bias in Motor Vehicle Searches: Additional Theory and Evidence

Knowles, Persico, and Todd (2001) develop a model of police search and offender behavior. Their model implies that if police are unprejudiced the rate of guilt should not vary across groups. Using data from Interstate 95 in Maryland, they find equal guilt rates for African-Americans and whites and conclude that the data is not consistent with racial prejudice against African-Americans. This paper generalizes the model of Knowles, Persico, and Todd by accounting for the fact that potential offenders are frequently not observed by the police and by including two different levels of offense severity. The paper shows that for African-American males the data is consistent with prejudice against African-American males, no prejudice, and reverse discrimination depending on the form of equilibria that exists in the economy. Additional analyses based on stratification by type of vehicle and time of day were conducted, but did not shed any light on the form of equilibria that best represents the situation in Maryland during the sample period.

Penalty Enhancement for Hate Crimes: An Economic Analysis

The issue of bias-motivated crimes has attracted consderable attention in recent years. In this paper, we develop an economic framework to analyze penalty enhancements for bias-motivated crimes. We extend the standard model by introducing two different groups of potential victims of crime, and assume that a potential offender's benefits from a crime depend on the group to which the victim belongs. We begin with the assumption that the harm to an individual victim from a bias-motivated crime is identical to that from an equivalent non-hate crime. Nonetheless, we derive the result that a pattern of crimes disproportionately targeting an identifiable group leads to greater social harm. This conclusion follows both from a model where disparities in groups' victimization probabilities lead to social losses due to fairness concerns, as well as a model where potential victims have the opportunity to undertake socially costly victimization avoidance activities. In particular, penalty enhancements can reduce the incentives for avoidance activity, and thereby protect the networks of profitable interactions that link members of different groups. We also argue that those groups that are covered by hate crime statutes tend to be those whose characteristics make it especially likely that penalty enhancement is socially optimal. Finally, we consider a number of other issues related to hate crimes, including teh choice of sanctions from behind a Rawlsian 'veil of ignorance' concerning group identity.

Joint Attention in Young Children with Autism

Autism spectrum disorders (ASDs) are classified as pervasive developmental disorders characterized by social, communicative, and behavioral impairments. According to formal and informal reports, children with ASD present with receptive and expressive language delay. Joint attention (JA: the behavior that occurs when two individuals focus on the same object or event) has been identified as a possible marker of delayed language development in children with ASD. In this study, the JA behaviors in children with ASD were contrasted with initially language-matched typically developing (TYP) children across three visits. Measures of language, the frequency, duration, and source of initiation of JA episodes, and the choice of toy during those episodes, were coded. Across visits and groups, mothers initiated more JA episodes than children; however, typical children also initiated more JA episodes than ASD children at visits 1 and 2. Also, the total duration of typically developing children’s JA episodes was generally longer than that of the ASD children’s, significantly so at Visit 2. Significant associations emerged between children’s vocabulary and two measures of JA: frequency and number of maternal initiations. Teaching parents to incorporate JA training in their interactions with their children may likely help children with ASD acquire language.