Mike Cassidy is an Assistant Professor of Pediatrics and Population Health Sciences and Policy in the Center for Child Health Services Research in the Mindich Child Health and Development Institute at the Icahn School of Medicine at Mount Sinai.
He is an applied microeconomist who uses the science of causal inference to study the social, economic, and environmental determinants of wellbeing across the lifespan. His current work focuses on housing, homelessness, education, and children’s health.
Prior to Mount Sinai, Mike was a postdoc and associate research scholar in the Center for Health and Wellbeing at Princeton University’s School of International and Public Affairs. He has also held positions at The Century Foundation and the NYC Office of Management and Budget.
PhD, Economics, 2020
Rutgers University
MPA, Economics and Public Policy, with distinction, 2014
Princeton University
BA, Communication and Political Science, summa cum laude, 2007
University of Pennsylvania
We identified children who resided in the New York City shelter system during 2015-2020 by matching address histories in Medicaid insurance claims to publicly available homeless shelter addresses, permitting examination of health care use before, during, and after shelter stays. We found that 4.5% of NYC children aged 4-17 with consistent Medicaid coverage entered shelter over a three-to-five-year period. After shelter entry, children had increased probabilities of receiving mental health services, including therapy and diagnoses of neurodevelopmental disorders, but little change in physical health service use. Children placed in shelters co-located with mental health services were similar to children entering other shelters prior to entry but had particularly large and sustained increases in use of mental health services afterwards. Children without prior mental health claims placed in shelters co-located with mental health services were 38-48% more likely to receive mental health therapy and 14-16% more likely to receive neurodevelopmental diagnoses than similar children placed elsewhere. These children were also more likely to receive Supplemental Security Income and stayed in shelter longer. This example illustrates the potential of linking administrative data sets in order to study vulnerable populations.
Housing is one of the areas where it may be most critical for poor people to have access to legal representation in civil cases. We use the roll out of New York City’s Universal Access to Counsel program (UA) to assess the effects of legal representation on tenant outcomes, using detailed address-level housing court data from 2016 to 2019. The program offers free legal representation in housing court to tenants with income at or below 200 percent of the federal poverty guideline. We find that tenants who gain lawyers are less likely to be subject to possessory judgments, face smaller monetary judgments, are less likely to have eviction warrants issued against them, and are less likely to be evicted. Lawyers have larger effects for tenants at higher risk of possessory judgment. Our results support the idea that legal representation in civil procedures can have important positive impacts on the lives of poor people.
Absenteeism is a prevailing concern in American education, and students experiencing homelessness are particularly vulnerable to high rates of school absenteeism. Despite this increased risk, we find no research in which the primary focus is assessing the efficacy of shelter-based programs that seek to reduce absenteeism among homeless children. Thus, we evaluate the Attendance Matters program, which sought to improve school attendance among homeless students in New York City shelters through interagency coordination, leveraging data to target scarce program resources, and employing evidence-based social work practices. We use administrative data in a quasi-experimental study to evaluate the program’s effects on school attendance and, secondarily, on outcomes of proficiency and stability. Findings suggest that the program resulted in reductions in days absent and the absence rate among K-8 students, though findings for secondary outcomes and attendance outcomes for high school students were inconsistent across model specifications. Results, which likely understate actual program effects, have implications beyond this setting, as they suggest that a low-budget program leveraging evidence-based practices and existing resources can impact this seemingly intractable problem. Education and homelessness policymakers should seek opportunities to test replication in additional settings.
More than one million students in the United States experience homelessness annually. Among their challenges is getting to school. This paper uses novel administrative data and a natural experiment in shelter scarcity to assess the effects of school proximity. For the average homeless K-8 student, a 10-mile longer commute leads to 6-13 percent more absences, a quarter higher probability of changing schools, and a decline in math test scores of 0.03-0.11 standard deviations. A complementary difference-in-differences design reinforces the importance of distance. The prevalence of housing instability in public schools suggests broad policy relevance.
Using an original administrative dataset in the context of a scarcity induced-natural experiment in New York City, I find that families placed in shelters in their neighborhoods of origin remain there considerably longer than those assigned to distant shelters. Locally-placed families also access more public benefits and are more apt to work. A fixed effects model assessing multi-spell families confirms these main results. Complementary instrumental variable and regression discontinuity designs exploiting policy shocks and rules, respectively, suggest difficult-to-place families—such as those that are large, disconnected from services, or from neighborhoods where homelessness is common—are especially sensitive to proximate placements. Better targeting through improved screening at intake can enhance program efficiency. The practice of assigning shelter based on chance vacancies ought to be replaced with a system of evidence-based placements tailored to families’ resources and constraints.
Despite consensus among medical authorities about the desirability of breastfeeding, causal evidence about its effects is scant. Using complementary empirical approaches and data from the National Longitudinal Survey of Youth spanning five decades, I investigate a comprehensive set of outcomes with greater breadth and continuity than previous work. On average, breastfeeding is associated with modest and persistent cognitive advantages from childhood through young adulthood—even after controlling for an extensive set of confounding forces. Accounting for breastfeeding duration strengthens these relationships and uncovers favorable labor market and fertility linkages as well. But there is no evidence for enduring health benefits. At the same time, a novel extended family fixed effects analysis comparing differentially breastfed siblings and cousins finds little association between breastfeeding and any outcome. These divergent results may reflect omitted variable bias in conventional estimates, but they may also be the consequence of considerable negative selection among the inconsistently breastfeeding families contributing to fixed effects identification.
There is growing recognition of the importance of mental health among children and youth and impacts on the affected individuals. However, little is understood about how the mental health experiences of children affect their siblings and parents. In this paper, we study the intrafamily effects of new diagnoses of childhood depression and anxiety. Using a decade of detailed claims from a large U.S. health insurer, we examine outcomes including overall physical and mental health and health care consumption, as well as a number of specific conditions. We exploit the conditionally random timing of mental health events to identify causal relationships and mechanisms.
More than half a million prisoners are released from state and federal prisons each year. Formerly incarcerated people are nearly ten times more likely to experience homelessness than the general population, and the risk is highest in the first two years after leaving prison. Permanent supportive housing (PSH), a popular housing-first strategy for achieving stability and independence among populations at risk of homelessness, provides affordable housing and support services to some 375,000 people in the United States each year, without time limits. In partnership with the Corporation for Supportive Housing (CSH) in Ohio, we conduct the first randomized controlled trial of PSH for exiting prisoners at risk of homelessness. Outcomes of interest include criminal recidivism, housing stability, health, income, and employment. The RCT began enrollment during the summer of 2023.
The scoring system most commonly used to prioritize people experiencing homelessness for scarce housing and services—the Vulnerability Index - Service Prioritization Decision Assistance Tool (VI-SPDAT)—is widely seen as flawed. Using machine learning, we develop a simplified, data-driven algorithm that easily outperforms the VI-SPDAT. We then test the effectiveness of this new tool by conducting a randomized controlled trial comparing data-driven prioritization with the vulnerability ratings given by skilled assessors. Outcomes of interest include housing stability, returns to homelessness, creditworthiness and use of credit, criminal justice involvement, employment, and income. The RCT began in November 2022 and preliminary results are expected in winter 2023-24; thus far, several thousand individuals have been prioritized. A second phase of the study will allow clients to express preferences over placements. Results will inform the development of an optimal hybrid tool combining insights from data, experts, and clients. The objective is to reduce homelessness and improve housing stability by identifying the people at greatest risk of remaining homeless without housing assistance.
There is growing interest in direct cash transfers as a means of addressing poverty and housing instability. However, there is little research on such programs, particularly in the United States. This study evaluates the Trust Youth Initiative, a “cash plus” intervention for addressing young adult homelessness and bolstering housing and racial justice. Collaboratively developed by Chapin Hall at the University of Chicago, Point Source Youth, Larkin Street Youth Services, and young adult partners with lived expertise, the TYI includes 24 months of unconditional direct cash transfers designed to support stable housing, along with optional, youth-driven supportive programming (e.g., peer support, housing navigation, and financial coaching). Enrollment has been completed and survey data is being collected. The evaluation will study housing, health, and human capital outcomes for at least 30 months following enrollment. It is also part of an emerging multi-site cohort of similar trials across the country.
The Americans with Disabilities Act (ACA) requires public transit agencies to provide comparable paratransit services to riders with disabilities. However, unlike fixed-route transit riders who can generally take trips on-demand, paratransit users are often required to book trips a day in advance, constraining their mobility. In partnership with King County Metro (KCM), we conduct a randomized controlled evaluation of a same-day-service (SDS) paratransit pilot in King County, Washington, an area encompassing Seattle and 38 other cities. Outcomes of interest include mobility, health, and wellbeing, which are to be measured through surveys and administrative data. The project is currently in a pre-pilot phase designed to collect evidence for the full RCT, which is expected to launch in the spring of 2024.
It has long been observed that individuals who participate in endurance sports also tend to excel intellectually. More broadly, young athletes, regardless of sport, tend to academically outperform their sedentary peers, and these educational differences persist into adulthood, with implications for earnings and employment. Nevertheless, few studies provide convincing evidence that this association is causal. This study exploits quasi-random variation in the introduction of a youth running program—Rising New York Road Runners (RNYRR)—in New York City public schools to identify the causal effect of aerobic exercise on short- and medium-term educational performance and health.
Los Angeles, California, has the second largest homeless population in the United States and among the highest rates of unsheltered homelessness of any major city. Consequently, LA has enacted a number of expensive, high-profile policies to adddress homelessness in recent years (e.g., a $1.2 billion bond to develop permanent supportive housing.) Quasi-randomness in the timing and geography of these initiatives—in combination with acute housing scarcity—create a number of natural experiments. This project uses these experiments and an administrative data enclave hosted by the California Policy Lab to gain a better understanding of causal relationships in homelessness and provide policy-relevant insights.