A distinction between causal effects in structural and rubin causal models
Structural Causal Models define causal effects in terms of a single Data Generating Process (DGP), and the Rubin Causal Model defines causal effects in terms of a model that can represent counterfactuals from many DGPs. Under these different definitions, notationally similar causal effects make distinct claims about the results of interventions to the system under investigation: Structural equations imply conditional independencies in the data that potential outcomes do not. One implication is that the DAG of a Rubin Causal Model is different from the DAG of a Structural Causal Model. Another ...
Assessing the Evidence on Neighborhood Effects from Moving to Opportunity
The Moving to Opportunity (MTO) experiment randomly assigned housing vouchers that could be used in low-poverty neighborhoods. Consistent with the literature, I find that receiving an MTO voucher had no effect on outcomes like earnings, employment, and test scores. However, after studying the assumptions identifying neighborhood effects with MTO data, this paper reaches a very different interpretation of these results than found in the literature. I first specify a model in which the absence of effects from the MTO program implies an absence of neighborhood effects. I present theory and ...
The Opioid Epidemic and the Labor Market
Drug overdoses now account for more deaths in the United States than traffic deaths or suicides, and most of the increase in overdose deaths since 2010 can be attributed to opioids--a class of drugs that includes both prescription pain relievers and illegal narcotics. We look at trends in drug use and overdose deaths to document how the opioid epidemic has evolved over time and to determine whether it could be large enough to impact the labor force.
The Dynamics of the Racial Wealth Gap
We reconcile the large and persistent racial wealth gap with the smaller racial earnings gap, using a general equilibrium heterogeneous-agents model that matches racial differences in earnings, wealth, bequests, and returns to savings. Given initial racial wealth inequality in 1962, our model attributes the slow convergence of the racial wealth gap primarily to earnings, with much smaller roles for bequests or returns to savings. Cross-sectional regressions of wealth on earnings using simulated data produce the same racial gap documented in the literature. One-time wealth transfers have only ...
Landlords and Access to Opportunity
Landlords in high-opportunity neighborhoods screen out tenants using vouchers. In our correspondence experiment, signaling voucher status cuts landlord responses in half. This voucher penalty increases with posted rent and varies little with signals of tenant quality and race. We repeat the experiment after a policy change and test how landlords respond to raising voucher payment limits by $450 per month in high-rent neighborhoods. Most landlords do not change their screening behavior; those who do respond are few and operate at small scale. Our results suggest a successful, systematic policy ...
When should children start school?
Kindergarten-entrance-age effects are difficult to identify due to the nonrandom allocation of entrance-age and simultaneous relative-age effects. This paper presents evidence that instrumental variable frameworks do not identify age effects for the youngest children of a cohort using the results of statistical tests for essential heterogeneity in initial enrollment decisions. Restricting attention to the oldest children in a cohort yields a sample with quasirandom variation in entrance and relative ages. This variation is used to identify the parameters of education production functions in ...
Evidence on the Production of Cognitive Achievement from Moving to Opportunity
This paper performs a subgroup analysis on the effect of receiving a Moving to Opportunity (MTO) housing voucher on test scores. I find evidence of heterogeneity by number of children in the household in Boston, gender in Chicago, and race/ethnicity in Los Angeles. To study the mechanisms driving voucher effect heterogeneity, I develop a generalized Rubin Causal Model and propose an estimator to identify transition-specific Local Average Treatment Effects (LATEs) of school and neighborhood quality. Although I cannot identify such LATEs with the MTO data, the analysis demonstrates that ...
Racial Inequality, Neighborhood Effects, and Moving to Opportunity
Moving to Opportunity (MTO) was a housing mobility program designed to investigate neighborhood effects, the influences of the social and physical environment on human development and well-being. Some of the results from MTO have been interpreted as evidence that neighborhood effects are not as strong as earlier evidence had indicated. This Commentary discusses new research suggesting that neighborhood effects are, on the contrary, as strong and policy relevant as suspected before the experiment. This Commentary also discusses why the interpretation of the MTO data is important: If ...
What Is the Equity-Efficiency Tradeoff when Maintaining Wells in Rural Haiti?
This paper quantitatively compares water infrastructure interventions that prioritize equity with those that prioritize efficiency. The community-based model developed by Haiti Outreach (HO) trains communities to operate and maintain wells, and has clear effi ciency gains over the status quo aid model in Haiti that gives communities wells: HO?s wells were 8.7 percentage points more likely to be functioning after one year than similarly-constructed wells managed under the status quo model. Because HO?s model includes user fees, which raise concerns about equity, I quantify the ...
The growing difference in college attainment between women and men
Workers with more education typically earn more than those with less education, and the difference has been growing in recent decades. Not surprisingly, the percentage of the population going after and getting a college degree has been rising as well. Since the late 1970s, though, the increase in college attainment has stalled for men and gathered steam for women. Among college-age individuals, more women now graduate than men. Changes in labor market incentives appear to explain the increased investment in education made by women. But men?s investments in education have been much less ...