Black Suburbanization: Causes and Consequences of a Transformation of American Cities

Since 1970, the share of Black individuals living in suburbs of larger cities has risen from 16 to 36 percent. We study the causes and consequences of this shift, which involved as many people as the post-World War II wave of the Great Migration. We show that Black suburbanization is widespread across regions and suburban neighborhood types, while Black and total population have declined drastically in historically majority-Black city neighborhoods. A neighborhood choice model suggests that changes in relative housing prices and amenities each explain 30 to 50 percent of the shift to the suburbs, while rising education levels and regional reallocation together explain 10 percent. Next, we find that suburbanization accounts for over half of both the recent increase in within-Black income segregation and the improvement in the average Black household’s neighborhood quality. Suburbanization’s association with stratification is partially explained by low White flight and differentials in the supply of low-cost housing

The impact of COVID-19 on small business outcomes and expectations

To explore the impact of coronavirus disease 2019 (COVID-19) on small businesses, we conducted a survey of more than 5,800 small businesses between March 28 and April 4, 2020. Several themes emerged. First, mass layoffs and closures had already occurred—just a few weeks into the crisis. Second, the risk of closure was negatively associated with the expected length of the crisis. Moreover, businesses had widely varying beliefs about the likely duration of COVID-related disruptions. Third, many small businesses are financially fragile: The median business with more than $10,000 in monthly expenses had only about 2 wk of cash on hand at the time of the survey. Fourth, the majority of businesses planned to seek funding through the Coronavirus Aid, Relief, and Economic Security (CARES) Act. However, many anticipated problems with accessing the program, such as bureaucratic hassles and difficulties establishing eligibility. Using experimental variation, we also assess take-up rates and business resilience effects for loans relative to grants-based programs. © 2020 National Academy of Sciences. All rights reserved

Curcuminoid Binding to Embryonal Carcinoma Cells: Reductive Metabolism, Induction of Apoptosis, Senescence, and Inhibition of Cell Proliferation

Curcumin preparations typically contain a mixture of polyphenols, collectively referred to as curcuminoids. In addition to the primary component curcumin, they also contain smaller amounts of the co-extracted derivatives demethoxycurcumin and bisdemethoxycurcumin. Curcuminoids can be differentially solubilized in serum, which allows for the systematic analysis of concentration-dependent cellular binding, biological effects, and metabolism. Technical grade curcumin was solubilized in fetal calf serum by two alternative methods yielding saturated preparations containing either predominantly curcumin (60%) or bisdemethoxycurcumin (55%). Continual exposure of NT2/D1 cells for 4–6 days to either preparation in cell culture media reduced cell division (1–5 µM), induced senescence (6–7 µM) or comprehensive cell death (8–10 µM) in a concentration-dependent manner. Some of these effects could also be elicited in cells transiently exposed to higher concentrations of curcuminoids (47 µM) for 0.5–4 h. Curcuminoids induced apoptosis by generalized activation of caspases but without nucleosomal fragmentation. The equilibrium binding of serum-solubilized curcuminoids to NT2/D1 cells incubated with increasing amounts of curcuminoid-saturated serum occurred with apparent overall dissociation constants in the 6–10 µM range. However, the presence of excess free serum decreased cellular binding in a hyperbolic manner. Cellular binding was overwhelmingly associated with membrane fractions and bound curcuminoids were metabolized in NT2/D1 cells via a previously unidentified reduction pathway. Both the binding affinities for curcuminoids and their reductive metabolic pathways varied in other cell lines. These results suggest that curcuminoids interact with cellular binding sites, thereby activating signal transduction pathways that initiate a variety of biological responses. The dose-dependent effects of these responses further imply that distinct cellular pathways are sequentially activated and that this activation is dependent on the affinity of curcuminoids for the respective binding sites. Defined serum-solubilized curcuminoids used in cell culture media are thus suitable for further investigating the differential activation of signal transduction pathways

Essays on the economics of labor markets

Thesis: Ph. D., Massachusetts Institute of Technology, Department of Economics, 2017.Cataloged from PDF version of thesis.Includes bibliographical references (pages 275-289).This thesis consists of three chapters on the economics of labor markets. Each chapter explores an aspect of the distributional consequences of labor market shocks due to changes in trade, regulations, or technology. The first chapter investigates the extent to which geographic variation in wage growth reflects workers' incomplete arbitrage of changing job opportunities in different locations, industries, and occupations. Without moving costs, worker adjustment to changes in labor demand would eliminate differential earnings effects between directly exposed workers and others in the same skill group. I find evidence against this full-mobility benchmark, estimating that exposure to trade with China reduces earnings of non-college educated workers in exposed Commuting Zones (CZs) by 4%, and fracking increases earnings of the original residents of exposed CZs by 7%. I estimate a model of location, sector, and occupation choice to quantify the costs that rationalize this incomplete arbitrage. Simulations show that halving these moving costs would have reduced the effect of exposure to trade with China by 35%. In the second chapter, Scott Nelson and I study recent bans on employers' use of credit reports to screen job applicants. Exploiting geographic, temporal, and job-level variation in which workers are covered by these bans, we find that the bans reduced job-finding rates for blacks by 7 to 16 log points, and increased separation rates for black new hires by 3 percentage points. We interpret these findings in a statistical discrimination model in which credit report data provides employers with a higher precision signal of workers' skills, compared to employers' prior beliefs and knowledge about workers' skills; this signal has particularly strong effects on blacks' employment outcomes. In the third chapter, Janet Currie, Christopher Knittel, Michael Greenstone, and I investigate the local welfare consequences of hydraulic fracturing. Exploiting geological and temporal variation, we find that allowing fracking leads to improvements in a wide set of economic indicators. At the same time, estimated willingness-to-pay (WTP) for the decrease in local amenities is equal to $1000 to$1,600 per household annually. Overall, we estimate that the WTP for allowing fracking equals $1,300 to$1,900 per household annually.by Alexander Wickman Bartik.1. Worker Adjustment to Changes in Labor Demand: Evidence from Longitudinal Census Data -- 2. Credit Reports as Résumés: The Incidence of Pre-Employment Credit Screening -- 3. The Local Economic and Welfare Consequences of Hydraulic Fracturing.Ph. D

The Local Economic and Welfare Consequences of Hydraulic Fracturing

© 2019 American Economic Association. Exploiting geological variation and timing in the initiation of hydraulic fracturing, we find that fracking leads to sharp increases in oil and gas recovery and improvements in a wide set of economic indicators. There is also evidence of deterioration in local amenities, which may include increases in crime, noise, and traffic and declines in health. Using a Rosen-Roback-style spatial equilibrium model to infer the net welfare impacts, we estimate that willingness-to-pay (WTP) for allowing fracking equals about $2,500 per household annually (4.9 percent of household income), although WTP is heterogeneous, ranging from more than$10,000 to roughly 0 across 10 shale regions

Job Postings, Applications, and Wages: Evidence from Homebase

As COVID-19 cases decline, vaccination rates rise, and pandemic-related restrictions are relaxed, the American labor market is recovering from the large job losses that occurred in March and April 2020. There has been particular interest in how employment is recovering in retail, hospitality, and food services—the sectors that experienced the largest declines in employment at the start of the pandemic.We’re working with Homebase data to better understand how workers and firms in these sectors have been responding to the reopening of the economy. Homebase provides timecard, scheduling, and other workforce management services to small and medium-sized businesses, many in the food services and retail sectors.  As part of these services, Homebase provides a hiring tool to their client firms that allows them to post job openings on all the main hiring websites and aggregate applications received across these hiring websites.These hiring tool data allow us to measure at high-frequency how job posts and applications are evolving at small and medium-sized businesses providing in-person services (see our previous post and paper documenting the characteristics of Homebase clients in general for more information). These businesses are heavily concentrated in sectors like food and drink and retail that have been most impacted by the COVID-19 crisis. Their jobs typically require in-person work, potentially raising concerns about virus exposure risks; offer relatively modest wages, with average offered hourly wages around $12-15; and require little in the way of formal training or credentials.This work has been supported, in part, by the University of California Multicampus Research Programs and Initiatives grants MRP-19-600774 and M21PR3278