Neighborhoods and the Black-White Mobility Gap

Analyzes the impact of neighborhood poverty rates during childhood on relative intergenerational economic mobility and how changes in poverty rates affect incomes, earnings, and wealth as adults. Outlines policy implications for closing the racial gap

Mobility and the Metropolis: How Communities Factor Into Economic Mobility

This report shows that neighborhoods play an important role in determining a family's prospects of moving up the economic ladder. Metropolitan areas where the wealthy and poor live apart have lower mobility than areas where residents are more economically integrated

Neighborhood Inequality and Violence in Chicago, 1965–2020

This Essay analyzes trends in violence from a spatial perspective, focusing on how changes in the murder rate are experienced by communities and groups of residents within the city of Chicago. The Essay argues that a spatial perspective is essential to understanding the causes and consequences of violence in the United States and begins by describing the social policies and theoretical mechanisms that explain the connection between concentrated disadvantage and violent crime. The analysis expands on a long tradition of research in Chicago, and it studies the distribution of violence in the city’s neighborhoods from 1965 to 2020. It additionally analyzes how the concentration of violence is overlaid with police violence and incarceration, creating areas of compounded disadvantage. Finally, it com-pares the recent trends of violence in Chicago with trends across the hundred largest cities in the United States. This Essay concludes that addressing the challenge of extreme, persistent segregation by race, ethnicity, and income across Chicago’s neighborhoods is necessary for producing a sustained reduction both in the city’s overall level of violence and in the disparities in the levels of violence faced by different neighborhoods

Destination Effects: Residential Mobility and Trajectories of Adolescent Violence in a Stratified Metropolis

Two landmark policy interventions to improve the lives of youth through neighborhood mobility—the Gautreaux program in Chicago and the Moving to Opportunity (MTO) experiments in five cities—have produced conflicting results and have created a puzzle with broad implications: Do residential moves between neighborhoods increase or decrease violence, or both? To address this question, we analyze data from a subsample of adolescents ages 9–12 years from the Project on Human Development in Chicago Neighborhoods, a longitudinal study of children and their families that began in Chicago—the site of the original Gautreaux program and one of the MTO experiments. We propose a dynamic modeling strategy to separate the effects of residential moving across three waves of the study from dimensions of neighborhood change and metropolitan location. The results reveal countervailing effects of mobility on trajectories of violence; whereas neighborhood moves within Chicago lead to an increased risk of violence, moves outside the city reduce violent offending and exposure to violence. The gap in violence between movers within and outside Chicago is explained not only by the racial and economic composition of the destination neighborhoods but also by the quality of school contexts, adolescents' perceived control over their new environment, and fear. These findings highlight the need to simultaneously consider residential mobility, mechanisms of neighborhood change, and the wider geography of structural opportunity.Sociolog

A simulation environment for multiple project resource optimization

Thesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, 2004.Vita.Includes bibliographical references (p. 98-99).This thesis develops a numerical simulation environment as a management support tool applicable to the selection and scheduling of multiple, concurrent research and development projects under conditions of constrained resources and uncertain program requirements. A prototype version of this software tool, called SEMPRO (Simulation Environment for Multiple Project Resource Optimization), is developed to capture an operational model of the NASA Dryden Flight Research Center flight and a representative research project portfolio. An attribute-driven Work Breakdown Schedule generates resource-loaded activity networks for each entry in the research project portfolio. The project selection and project coordination problems are formulated as Binary Integer Linear Programming problems, as extensions of the traditional Resource Constrained Project Scheduling Problem (RCPSP). To alleviate the computational obstacles associated with these NP Hard problems, a Lagrange Relaxation formulation is used to generate a near-optimal, time-phased sequence for execution of the selected project activity networks. Stochastic, non-linear, discrete-event simulation dynamics are then employed to validate these linear optimization solutions against a representative model of the organization's research and development project operational processes. The SEMPRO prototype is written in the Microsoft Excel Visual Basic Application language to facilitate project management visualization and knowledge transfer.by John Patrick Sharkey.S.M

The Academic Effects of Chronic Exposure to Neighborhood Violence

We estimate the causal effect of repeated exposure to violent crime on test scores in New York City. We use two distinct empirical strategies; value-added models linking student performance on standardized exams to violent crimes on a student’s residential block, and a regression discontinuity approach that identifies the acute effect of an additional crime exposure within a one-week window. Exposure to violent crime reduces academic performance. Value added models suggest the average effect is very small; approximately -0.01 standard deviations in English Language Arts (ELA) and mathematics. RD models suggest a larger effect, particularly among children previously exposed. The marginal acute effect is as large as -0.04 standard deviations for students with two or more prior exposures. Among these, it is even larger for black students, almost a 10th of a standard deviation. We provide credible causal evidence that repeated exposure to neighborhood violence harms test scores, and this negative effect increases with exposure

C₂N₂ vertical profile in Titan's stratosphere

In this paper, we present the first measurements of the vertical distribution of cyanogen (${{\rm{C}}}_{2}{{\rm{N}}}_{2}$) in Titan's lower atmosphere at different latitudes and seasons, using Cassini's Composite Infrared Spectrometer far-infrared data. We also study the vertical distribution of three other minor species detected in our data: methylacetylene (${{\rm{C}}}_{3}{{\rm{H}}}_{4}$), diacetylene (${{\rm{C}}}_{4}{{\rm{H}}}_{2}$), and ${{\rm{H}}}_{2}{\rm{O}}$, in order to compare them to ${{\rm{C}}}_{2}{{\rm{N}}}_{2}$, but also to get an overview of their seasonal and meridional variations in Titan's lower stratosphere from 85 km to 225 km. We measured an average volume mixing ratio of ${{\rm{C}}}_{2}{{\rm{N}}}_{2}$ of $6.2\pm 0.8\times {10}^{-11}$ at 125 km at the equator, but poles exhibit a strong enrichment in ${{\rm{C}}}_{2}{{\rm{N}}}_{2}$ (up to a factor 100 compared to the equator), greater than what was measured for ${{\rm{C}}}_{3}{{\rm{H}}}_{4}$ or ${{\rm{C}}}_{4}{{\rm{H}}}_{2}$. Measuring ${{\rm{C}}}_{2}{{\rm{N}}}_{2}$ profiles provides constraints on the processes controlling its distribution, such as bombardment by Galactic Cosmic Rays which seem to have a smaller influence on ${{\rm{C}}}_{2}{{\rm{N}}}_{2}$ than predicted by photochemical models

Durable Effects of Concentrated Disadvantage on Verbal Ability among African-American Children

Disparities in verbal ability, a major predictor of later life outcomes, have generated widespread debate, but few studies have been able to isolate neighborhood-level causes in a developmentally and ecologically appropriate way. This study presents longitudinal evidence from a large-scale study of >2,000 children ages 6–12 living in Chicago, along with their caretakers, who were followed wherever they moved in the U.S. for up to 7 years. African-American children are exposed in such disproportionate numbers to concentrated disadvantage that white and Latino children cannot be reliably compared, calling into question traditional research strategies assuming common points of overlap in ecological risk. We therefore focus on trajectories of verbal ability among African-American children, extending recently developed counterfactual methods for time-varying causes and outcomes to adjust for a wide range of predictors of selection into and out of neighborhoods. The results indicate that living in a severely disadvantaged neighborhood reduces the later verbal ability of black children on average by ≈ 4 points, a magnitude that rivals missing a year or more of schooling.Sociolog