RESUMO
Residential and school segregation have historically mirrored each other, with school segregation seen as simply reflecting residential patterns given neighborhood-based school assignment policy. We argue that the relationship is circular, such that school options also influence residential outcomes. We hypothesize that the expansion of charter schools could simultaneously lead to an increase in school segregation and a decrease in residential segregation. We examine what happens when neighborhood and school options are decoupled via public school choice in the form of charter schools using data from the census and the Common Core of Data on a national sample of more than 1,500 metropolitan districts. We find that Black-White school segregation increased and residential segregation declined in response to increases in the charter enrollment share from 2000 to 2010. In districts with charter schools, the average increase in the charter enrollment share corresponded to a 12% increase in school segregation and 2% decline in residential segregation. We find no relationship between charter school expansion and school segregation between White and Hispanic students, perhaps because Hispanic students attend more racially diverse charters than White or Black students. White-Hispanic residential segregation declined as charter enrollment increased. Our results demonstrate that educational policy is consequential for both school and neighborhood population processes. When these two contexts are decoupled via public school choice, school and neighborhood segregation patterns move in opposite directions, rather than mirroring each other. Our findings also provide a cautionary lesson for unfettered expansion of choice without integration imperatives.
Assuntos
Negro ou Afro-Americano , Segregação Social , Hispânico ou Latino , Humanos , Características de Residência , Instituições AcadêmicasRESUMO
This article provides a rich longitudinal portrait of the financial and social resources available in the school districts of high- and low-income students in the United States from 1990 to 2014. Combining multiple publicly available data sources for most school districts in the United States, we document levels and gaps in school district financial resources-total per-pupil expenditures-and social resources-local rates of adult educational attainment, family structure, and adult unemployment-available to the average public school student at a variety of income levels over time. In addition to using eligibility for the National School Lunch Program as a blunt measure of student income, we estimate resource inequalities between income deciles to analyze resource gaps between affluent and poor children. We then examine the relationship between income segregation and resource gaps between the school districts of high- and low-income children. In previous work, the social context of schooling has been a theoretical but unmeasured mechanism through which income segregation may operate to create unequal opportunities for children. Our results show large and, in some cases, growing social resource gaps in the districts of high- and low-income students nationally and provide evidence that these gaps are exacerbated by income segregation. Conversely, per-pupil funding became more compensatory between high- and low-income students' school districts over this period, especially in highly segregated states. However, there are early signs of reversal in this trend. The results provide evidence that school finance reforms have been somewhat effective in reducing the consequences of income segregation on funding inequities, while inequalities in the social context of schooling continue to grow.
Assuntos
Renda/estatística & dados numéricos , Instituições Acadêmicas/economia , Meio Social , Adolescente , Criança , Feminino , Humanos , Estudos Longitudinais , Masculino , Fatores Socioeconômicos , Estados UnidosRESUMO
Several recent studies have concluded that residential segregation by income in the United States has increased in the decades since 1970, including a significant increase after 2000. Income segregation measures, however, are biased upward when based on sample data. This is a potential concern because the sampling rate of the American Community Survey (ACS)-from which post-2000 income segregation estimates are constructed-was lower than that of the earlier decennial censuses. Thus, the apparent increase in income segregation post-2000 may simply reflect larger upward bias in the estimates from the ACS, and the estimated trend may therefore be inaccurate. In this study, we first derive formulas describing the approximate sampling bias in two measures of segregation. Next, using Monte Carlo simulations, we show that the bias-corrected estimators eliminate virtually all of the bias in segregation estimates in most cases of practical interest, although the correction fails to eliminate bias in some cases when the population is unevenly distributed among geographic units and the average within-unit samples are very small. We then use the bias-corrected estimators to produce unbiased estimates of the trends in income segregation over the last four decades in large U.S. metropolitan areas. Using these corrected estimates, we replicate the central analyses in four prior studies on income segregation. We find that the primary conclusions from these studies remain unchanged, although the true increase in income segregation among families after 2000 was only half as large as that reported in earlier work. Despite this revision, our replications confirm that income segregation has increased sharply in recent decades among families with children and that income inequality is a strong and consistent predictor of income segregation.
Assuntos
Viés , Renda/tendências , Algoritmos , Censos , Feminino , Humanos , Renda/estatística & dados numéricos , Masculino , Inquéritos e Questionários , Estados UnidosRESUMO
OBJECTIVE: The goal of this analysis is to spatiotemporally identify and categorize areas in a large urban city according to Out-of-Hospital Cardiac Arrest (OHCA) rates and No Bystander CPR (NBCPR) risk levels. STUDY AREA AND PARTICIPANTS: The study comprised all cardiac arrests within the administrative geographic boundary of the City of Los Angeles. The final sample included 15,904 cases that were geolocated within 985 census tracts. MAIN OUTCOMES AND MEASURES: The primary outcome was stratification of census tracts into risk levels of OHCA and NBCPR by observed spatiotemporal patterns. RESULTS: Of 985 census tracts in the analytical sample, 182 census tracts (18.5%) were identified as having higher risk of OHCA and NBCPR. This assessment resulted in 129 census tracts in Tier 3 (moderate risk), 36 in Tier 2 (moderate-high risk), and 17 in Tier 1 (highest risk). Census tracts in Tiers 2 and 3 had higher amounts incident OHCA, while those in tier 1 had more OHCA events with NBCPR. These areas were largely contiguous and located in the Central and South areas of Los Angeles. CONCLUSIONS: Using a novel three-tiered neighborhood risk classification tool, specific neighborhoods have been identified in the second largest city in the U.S. with consistently high or accelerating rates of OHCA and low bystander CPR. Further study of bystander response and community-based public health campaigns are needed in these communities.
Assuntos
Reanimação Cardiopulmonar , Serviços Médicos de Emergência , Parada Cardíaca Extra-Hospitalar , Cidades , Humanos , Los Angeles/epidemiologia , Parada Cardíaca Extra-Hospitalar/epidemiologia , Análise Espaço-TemporalRESUMO
OBJECTIVES: To test the hypothesis that there is no difference between the actual mesiodistal root angulation and the mesiodistal root angulation as measured on the panoramic radiograph. MATERIALS AND METHODS: A typodont dentition was set up into a Class I occlusion. Wire struts were placed on the buccal surface of each tooth to represent their long axes. The dentition was fixed into a natural skull for imaging. The radiographic and true mesiodistal angulation of each tooth to a horizontal reference plane (the arch wire) was measured using a coordinate measuring machine (CMM). The mesiodistal root positions were then altered to a more mesial and then more distal position and the measurements were repeated. RESULTS: Only 26.7% of the radiographic root angulations were within the clinically acceptable angular variation range of +/-2.5 degrees . The greatest variation in the upper arch occurred in the canine-premolar area where the roots were projected as being more divergent. The greatest variation in the lower arch occurred in the lateral incisor-canine region where these roots were projected as being more convergent. The extent of radiographic distortion is statistically greater in the lower arch than in the upper arch in the ideal (P < or = .05) and distal (P < or = .01) root positions. CONCLUSIONS: The hypothesis is rejected. There is a clinically significant variation between the radiographic and the true root angulations recorded. Caution is advised when interpreting mesiodistal root angulation using this radiograph.