Early cognitive skills of Mexican-origin children: The roles of parental nativity and legal status

Although one-third of children of immigrants have undocumented parents, little is known about their early development. Using data from the Los Angeles Family and Neighborhood Survey and decennial census, we assessed how children's cognitive skills at ages 3 to 5 vary by ethnicity, maternal nativity, and maternal legal status. Specifically, Mexican children of undocumented mothers were contrasted with Mexican children of documented mothers and Mexican, white, and black children with U.S.-born mothers. Mexican children of undocumented mothers had lower emergent reading skills than all other groups and lower emergent mathematics skills than all groups with U.S.-born mothers. Multilevel regression models showed that differences in reading skills are explained by aspects of the home environment, but the neighborhood context also matters. Cross-level interactions suggest that immigrant concentration boosts emergent reading and mathematics skills for children with undocumented parents, but does not similarly benefit children whose parents are native born.     

On the number of local minima for the multidimensional assignment problem

The Multidimensional Assignment Problem (MAP) is an NP-hard combinatorial optimization problem occurring in many applications, such as data association, target tracking, and resource planning. As many solution approaches to this problem rely, at least partly, on local neighborhood search algorithms, the number of local minima affects solution difficulty for these algorithms. This paper investigates the expected number of local minima in randomly generated instances of the MAP. Lower and upper bounds are developed for the expected number of local minima, E[M], in an MAP with iid standard normal coefficients. In a special case of the MAP, a closed-form expression for E[M] is obtained when costs are iid continuous random variables. These results imply that the expected number of local minima is exponential in the number of dimensions of the MAP. Our numerical experiments indicate that larger numbers of local minima have a statistically significant negative effect on the quality of solutions produced by several heuristic algorithms that involve local neighborhood search.Partially supported by the NSF grant DMI-0457473.     

Girls’ self-efficacy in the context of neighborhood gender stratification

Scholars have linked neighborhood characteristics to self-efficacy, but few have considered how gender factors into this association. We integrate literature on neighborhoods, gender stratification, and self-efficacy to examine the association between women's relative resources among neighborhood residents and adolescents' self-efficacy. We hypothesize that girls report more self-efficacy when they reside in neighborhoods where women have more socioeconomic resources relative to men. We test this hypothesis using data from the Project on Human Development in Chicago Neighborhoods and the 1990 Census. Results from multilevel regression models with gender-interacted effects indicate the neighborhood level of women's relative resources was not associated with boys' self-efficacy. However, girls reported higher self-efficacy when women's relative resources in their neighborhoods were greater. This association persisted after including potential individual- and neighborhood-level confounding variables. Our study underscores the importance of attending to gendered processes when understanding how neighborhoods impact youth.     

Correlations among centrality indices and a class of uniquely ranked graphs

Various centrality indices have been proposed to capture different aspects of structural importance but relations among them are largely unexplained. The most common strategy appears to be the pairwise comparison of centrality indices via correlation. While correlation between centralities is often read as an inherent property of the indices, we argue that it is confounded by network structure in a systematic way. In fact, correlations may be even more indicative of network structure than of relationships between indices. This has substantial implications for the interpretation of centrality effects as it implies that competing explanations embodied in different indices cannot be separated from each other if the network structure is close to a certain generalization of star graphs.     

Toward increasing avian diversity: urban wildscapes programs

Residential development in urban and suburban settings is a major cause of habitat change affecting avian communities. The effects from land-clearing prior to initiation of construction followed by landscaping focused on traditional aesthetics has reduced habitat diversity at multiple levels. These residential developments generally emphasize the use of ornamental, nonindigenous vegetation with little to no concern for native species and natural vegetation parameters. As a result, avian community composition and diversity is changed. We compared avian communities at three sites in Bexar County, Texas; two residential neighborhoods in the city of San Antonio and an unincorporated undeveloped site, Government Canyon State Natural Area. The residential neighborhoods were a Texas Parks and Wildlife Department certified wildscapes development and a traditionally developed neighborhood. Bird abundance and species richness in the neighborhoods were greater than at Government Canyon State Natural Area (P < 0.01), but no differences existed between the neighborhoods. Bird diversity was greatest at the wildscapes neighborhood (P < 0.01). Further, bird diversity did not differ between the traditional neighborhood and the natural area. Evenness differed among sites (P = 0.006) with the natural area having the greatest value. Bird diversity measures correlated with woody plant density and vertical cover (r = 0.358 to 0.673, P < 0.05) at residential sites. Residential areas incorporating natural landscapes into their design attracted a greater variety of birds than traditionally landscaped residential areas.     

The estimation of neighborhood effects in the social sciences: An interdisciplinary approach

This paper critically examines the interdisciplinary research of neighborhood effects. Neighborhood effects are community influences on individual social or economic outcomes. Examples include labor force activity, child outcomes, criminal behavior, and other socioeconomic phenomena. The existing theoretical and empirical literature is reviewed. Conceptual definitions from sociology are linked and contrasted with economic models. Early studies are criticized for failing to account for a number of endogeneity concerns. Recent empirical studies are also explored. The results of these papers demonstrate that although neighborhood characteristics are important, their influences are much smaller than suggested by previous research. An additional emphasis is dedicated to linking the neighborhood effects literature to other research of local or spatial activity within economics, sociology, and geography. In particular, the potential employment of local interaction game theory and spatial econometrics in neighborhood effects research is discussed. Additionally, a catalogue of existing empirical research is assembled.     

Context,network, and adolescent perceived risk

Prior research has identified a list of individual attributes, along with neighborhood, school, and network characteristics, as potential factors affecting perceived risk. However, prior research has rarely investigated the simultaneous effects of these factors on perceived risk. This study uses the National Longitudinal Study of Adolescent Health (AddHealth), supplemented with the 1990 census data, to examine the associations of neighborhood, school, and network characteristics and perceived risk among adolescents. To account for the overlaps between school districts and neighborhoods, we use cross-classified multilevel modeling (CCMM). Our analyses lead to two main findings. First, perceived risk appears to be context-specific. Perceived risk at school is mostly affected by school characteristics but not by neighborhood characteristics. Perceived risk in neighborhood is mostly affected by neighborhood characteristics but not by school characteristics. Second, network characteristics matter for both types of perceived risk and more so for perceived risk at school than in neighborhood. We find that, while having more friends is associated with a lower level of perceived risk, having more friends with delinquent and violent behaviors is associated with a higher level of perceived risk among adolescents.     

Neighborhood poverty and children’s exposure to danger: Examining gender differences in impacts of the Moving to Opportunity experiment

The Moving to Opportunity (MTO) program offered public housing residents in distressed communities a chance to move to low-poverty neighborhoods. The present study examined whether the resulting decline in neighborhood poverty led to lower levels of exposure to danger among children and youth ages 8-19 years old (n = 4606), and specifically, if there was a gender difference that matched the pattern of more beneficial program effects for girls and more adverse affects for boys. The study goes beyond previous research by using fixed effects to control for family factors that may influence moving behavior and confound estimates of gender differences in program impacts. Results showed that children experienced a decline in exposure to danger, with one key gender difference. Models based on brother-sister comparisons indicated that MTO had a more beneficial impact on exposure to drug activity for females than males. The findings suggest that neighborhood poverty is tied to children’s exposure to danger. Moreover, exposure to drug activity may help explain the gender differences in impacts on children’s mental health and risky behavior.     

From neighbors to school friends? How adolescents’ place of residence relates to same-ethnic school friendships

This study examines to what extent adolescents’ place of residence is related to the opportunities and the preferences to befriend same-ethnic classmates. Analyzing 3345 students within 158 German and Dutch school classes, we find that sharing a neighborhood provides additional meeting opportunities to become friends in class as adolescents are likely to befriend classmates who live nearby them or who live nearby a friend of them (propinquity mechanism). However, this hardly explains why adolescent friendship networks in school classes tend to be ethnically homogeneous. Also, we find no convincing evidence that an adolescent's preference for same-ethnic friends in class varies with the share of outgroup members in his/her neighborhood (exposure mechanism).     

Neighborhoods, employment, and welfare use: Assessing the influence of neighborhood socioeconomic composition

We draw upon data from the Fragile Families and Child Well-Being Study to examine the effect of neighborhood socioeconomic composition on two key economic outcomes, and in doing so to test the validity of the index of concentration at the extremes (ICE) as a measure of neighborhood circumstances. Methodologically, we find that the index succinctly captures economic variation within neighborhoods in a way that avoids problems of colinearity that have characterized prior studies. Neighborhoods can be characterized as falling on a continuum ranging from concentrated disadvantage to concentrated advantage; the ICE measure does a good job capturing this variation and differentiating the neighborhood circumstances experienced by different groups. Substantively, we show that neighborhood economic circumstances are related to new mothers’ welfare use and employment, above and beyond their individual socioeconomic characteristics.