Joshua D. Angrist

• Professor at Massachusetts Institute of Technology

The ISCHEMIA Trial randomly assigned patients with ischemic heart disease to an invasive treatment strategy centered on revascularization with a control group assigned non-invasive medical therapy. As is common in such ``strategy trials,'' many participants assigned to treatment remained untreated while many assigned to control crossed over into tr...

Elite economics PhD programs aim to train graduate students for a lifetime of academic research. This paper asks how advising affects graduate students' post-PhD research productivity. Advising is highly concentrated: at the eight highly-selective schools in our study, a minority of advisors do most of the advising work. We quantify advisor attribu...

In large urban districts, schools enrolling more White students tend to have higher performance ratings. We use an instrumental variables strategy leveraging centralized school assignment to explore this relationship. Estimates from Denver and New York City suggest that the correlation between school performance ratings and White enrollment shares...

Pragmatic cancer screening trials mimic real-world scenarios in which patients and doctors are the ultimate arbiters of treatment. Intention-to-screen (ITS) analyses of such trials maintain randomization-based apples-to-apples comparisons, but differential adherence (the failure of subjects assigned to screening to get screened) makes ITS effects h...

Many schools in large urban districts have more applicants than seats. Centralized school assignment algorithms ration seats at over‐subscribed schools using randomly assigned lottery numbers, non‐lottery tie‐breakers like test scores, or both. The New York City public high school match illustrates the latter, using test scores and other criteria t...

The view that empirical strategies in economics should be transparent and credible now goes almost without saying. By revealing for whom particular instrumental variables (IV) estimates are valid, the local average treatment effects (LATE) framework helped make this so. This lecture uses empirical examples, mostly involving effects of charter and e...

Financial aid from the Susan Thompson Buffett Foundation (STBF) provides comprehensive support to a college population similar to that served by a host of state aid programs. In conjunction with STBF, we randomly assigned aid awards to thousands of Nebraska high school graduates from low-income, minority, and first-generation college households. Ra...

We introduce two empirical strategies harnessing the randomness in school assignment mechanisms to measure school value-added. The first estimator controls for the probability of school assignment, treating take-up as ignorable. We test this assumption using randomness in assignments. The second approach uses assignments as instrumental variables (...

Zusammenfassung Der Nobelpreis für Wirtschaftswissenschaften geht 2021 an David Card für seine empirischen Beiträge zur Arbeitsökonomik sowie an Joshua Angrist und Guido Imbens für ihre methodischen Beiträge zur Analyse kausaler Zusammenhänge. Die Analyse kausaler Zusammenhänge in der empirischen Ökonomik wurde durch die von den Preisträgern maßgeb...

Two-stage least squares estimates in heavily over-identified instrumental variables (IV) models can be misleadingly close to the corresponding ordinary least squares (OLS) estimates when many instruments are weak. Just-identified (just-ID) IV estimates using a single instrument are also biased, but the importance of weak-instrument bias in just-ID...

Many schools in large urban districts have more applicants than seats. Centralized school assignment algorithms ration seats at over-subscribed schools using randomly assigned lottery numbers, non-lottery tie-breakers like test scores, or both. The New York City public high school match illustrates the latter, using test scores and other criteria t...

Using nationally representative data from India I examine the labor market effects of world's biggest and arguably most aggressive form of employment based affirmative action policy for minorities. This paper exploits the institutional features of federally mandated employment quota policy to examine its effect on two distinct minority groups. My m...

Does academic economic research produce material of general scientific value, or do academic economists write only for peers? Is economics scholarship uniquely insular? We address these questions by quantifying interactions between economics and other disciplines. Changes in the influence of economic scholarship are measured here by the frequency w...

We use Maimonides’ rule as an instrument for class size in large Israeli samples from 2002–2011. In contrast with Angrist and Lavy (1999), newer estimates show no evidence of class size effects. The new data also reveal enrollment manipulation near Maimonides cutoffs. A modified rule that uses birthdays to impute enrollment circumvents manipulation...

The second chapter studies whether students prefer friends who are similar to them and whether these preferences persist when students have to interact frequently. I use network surveys and exploit variation in the exact position of the students in the allocation to dormitories at selective boarding schools in Peru. Students are more likely to form...

Instrumental variables (IV ) estimates show strong class-size effects in Southern Italy. But Italy's Mezzogiorno is distinguished by manipulation of standardized test scores as well as by economic disadvantage. IV estimates suggest small classes increase manipulation. We argue that score manipulation is a consequence of teacher shirking. IV estimat...

A growing number of school districts use centralized assignment mechanisms to allocate school seats in a manner that reflects student preferences and school priorities. Many of these assignment schemes use lotteries to ration seats when schools are oversubscribed. The resulting random assignment opens the door to credible quasi-experimental researc...

The past half-century has seen economic research become increasingly empirical, while the nature of empirical economic research has also changed. In the 1960s and 1970s, an empirical economist's typical mission was to "explain" economic variables like wages or GDP growth. Applied econometrics has since evolved to prioritize the estimation of specif...

We examine the evolution of economics research using a machine-learning-based classification of publications into fields and styles. The changing field distribution of publications would not seem to favor empirical papers. But economics' empirical shift is a within-field phenomenon; even fields that traditionally emphasize theory have gotten more e...

Many school and college admission systems use centralized mechanisms to allocate seats based on applicant preferences and school priorities. When tie-breaking uses non-randomly assigned criteria like distance or a test score, applicants with the same preferences and priorities are not directly comparable. The non-lottery setting does generate a kin...

Conventional value-added models (VAMs) compare average test scores across schools after regression-adjusting for students' demographic characteristics and previous scores. This article tests for VAM bias using a procedure that asks whether VAM estimates accurately predict the achievement consequences of random assignment to specific schools. Test r...

Charter takeovers are traditional public schools restarted as charter schools. We develop a grandfathering instrument for takeover attendance that compares students at schools designated for takeover with a matched sample of students attending similar schools not yet taken over. Grandfathering estimates from New Orleans show substantial gains from...

We develop flexible semiparametric time series methods for the estimation of the causal effect of monetary policy on macroeconomic aggregates. Our estimator captures the average causal response to discrete policy interventions in a macro-dynamic setting, without the need for assumptions about the process generating macroeconomic outcomes. The propo...

We develop over-identification tests that use admissions lotteries to assess the predictive value of regression-based value-added models (VAMs). These tests have degrees of freedom equal to the number of quasi-experiments available to estimate school effects. By contrast, previously implemented VAM validation strategies look at a single restriction...

We use admissions lotteries to estimate effects of attendance at Boston’s charter high schools on college preparation and enrollment. Charter schools increase pass rates on Massachusetts’ high-stakes exit exam, with large effects on the likelihood of qualifying for a statesponsored scholarship. Charter attendance also boosts SAT scores sharply and...

In an ongoing evaluation of post-secondary financial aid, we use random assignment to assess the causal effects of large privately-funded aid awards. Here, we compare the unbiased causal effect estimates from our RCT with two types of non-experimental econometric estimates. The first applies a selection-on-observables assumption in data from an ear...

In regression discontinuity (RD) studies of applicants who face an award or admissions cutoff, causal effects are nonparametrically identified for those near the cutoff. The effect of treatment on inframarginal applicants is also of interest, but identification of such effects requires stronger assumptions than those required for identification at...

We evaluate the effects of academic achievement awards for first-and second-year college students studying at a Canadian commuter college. The award scheme offered linear cash incentives for course grades above 70. Awards were paid every term. Program participants also had access to peer advising by upperclassmen. Program engagement appears to have...

Individual outcomes are highly correlated with group average outcomes, a fact often interpreted as a causal peer effect. Without covariates, however, outcome-on-outcome peer effects are vacuous, either unity or, if the average is defined as a leave-out mean, determined by a generic intraclass correlation coefficient. When pre-determined peer charac...

Applied econometrics, known to aficionados as 'metrics, is the original data science. 'Metrics encompasses the statistical methods economists use to untangle cause and effect in human affairs. Through accessible discussion and with a dose of kung fu-themed humor, Mastering 'Metrics presents the essential tools of econometric research and demonstrat...

In the canonical regression discontinuity (RD) design for applicants who face an award or admissions cutoff, causal effects are nonparametrically identified for those near the cutoff. The impact of treatment on inframarginal applicants is also of interest, but identification of such effects requires stronger assumptions than are required for identi...

We develop semiparametric tests for conditional independence in time series models of causal effects. Our approach is motivated by empirical studies of monetary policy effects and is semiparametric in the sense that we model the process determining the distribution of treatment—the policy propensity score—but leave the model for outcomes unspecifie...

Estimates using admissions lotteries suggest that urban charter schools boost student achievement, while charter schools in other settings do not. We explore student-level and school-level explanations for these differences using a large sample of Massachusetts charter schools. Our results show that urban charter schools boost achievement well beyo...

Talented students compete fiercely for seats at Boston and New York exam schools. These schools are characterized by high levels of peer achievement and a demanding curriculum tailored to each district's highest achievers. While exam school students do very well in school, the question of whether an exam school education adds value relative to a re...

The long-term consequences of Vietnam- era conscription have been extensively studied but are still changing. Estimates from the 2000 census, reported in Joshua D. Angrist and Stacey H. Chen (2011), suggest the large civilian earnings losses documented by Angrist (1990) for the 1970s and early 1980s had faded by 1999. At the same time, researchers...

Draft-lottery estimates of the consequences of Vietnam-era service using 2000 census data show marked schooling gains for veterans. We argue that these gains can be attributed to Vietnam veterans’ use of the GI Bill rather than draft avoidance behavior. At the same time, draft lottery estimates of the earnings consequences of Vietnam-era service ar...

We evaluate the effects of academic achievement awards for first and second-year college students on a Canadian commuter campus. The award scheme offered linear cash incentives for course grades above 70. Awards were paid every term. Program participants also had access to peer advising by upperclassmen. Program engagement appears to have been high...

This paper develops a covariate-based approach to the external validity of instrumental variables (IV) estimates. Assuming that differences in observed complier characteristics are what make IV estimates differ from one another and from parameters like the effect of treatment on the treated, we show how to construct estimates for new subpopulations...

This paper develops basic algebraic concepts for instrumental variables (IV) regressions which are used to derive the leverage and inuence of observations on the 2SLS estimate and compute alternative heteroskedasticity-consistent (HC1-HC3) estimators for the 2SLS covariance matrix in a …nite-sample context. In the second part, Monte Carlo simulatio...

The charter school landscape includes a variety of organizational models and a few national franchises. The nation’s largest network of charter schools is the Knowledge is Power Program (KIPP), with 80 schools operating or slated to open soon. KIPP schools target low income and minority students and subscribe to an approach some have called No Excu...

Just over a quarter century ago, Edward Leamer (1983) reflected on the state of empirical work in economics. He urged empirical researchers to “take the con out of econometrics” and memorably observed (p. 37): “Hardly anyone takes data analysis seriously. Or perhaps more accurately, hardly anyone takes anyone else’s data analysis seriously.” Leamer...

Since Edward Leamer's memorable 1983 paper, "Let's Take the Con out of Econometrics," empirical microeconomics has experienced a credibility revolution. While Leamer's suggested remedy, sensitivity analysis, has played a role in this, we argue that the primary engine driving improvement has been a focus on the quality of empirical research designs....

This paper presents novel empirical evidence on the impact of access to abortion on sex ratios at birth (SRB), excess female mortality (EFM) and fertility in Taiwan. For identification, we exploit plausibly exogenous variation in the availability of sex-selective abortion caused by the legalization of abortion. Our results show that the legalizatio...

Since the 1970s almost all US states have introduced a form of joint custody after divorce. I analyze the causal effect of these custody law reforms on different family outcomes. My identification strategy exploits the different timing of reforms across the US states. Esti-mations based on state panel data suggest that the introduction of joint cus...

A ‘treatment effect’ is the average causal effect of a binary (0–1) variable on an outcome variable of scientific or policy interest. The term ‘treatment effect’ originates in a medical literature concerned with the causal effects of binary, yes-or-no ‘treatments’, such as an experimental drug or a new surgical procedure. But the term is now used m...

Charter schools affiliated with the Knowledge is Power Program (KIPP) are emblematic of the No Excuses approach to public education. These schools feature a long school day, an extended school year, selective teacher hiring, strict behavior norms and a focus on traditional reading and math skills. We use applicant lotteries to evaluate the impact o...

The Israeli matriculation certificate is a prerequisite for most postsecondary schooling. In a randomized trial, we attempted to increase certification rates among low-achievers with cash incentives. The experiment used a school-based randomization design offering awards to all who passed their exams in treated schools. This led to a substantial in...

The veterans disability compensation (VDC) program, which provides a monthly stipend to disabled veterans, is the third largest American disability insurance program. Since the late 1990s, VDC growth has been driven primarily by an increase in claims from Vietnam veterans, raising concerns about costs as well as health. We use the draft lottery to...

This paper reports on an experimental evaluation of strategies designed to improve academic performance among college freshmen. One treatment group was offered academic support services. Another was offered financial incentives for good grades. A third group combined both interventions. Service use was highest for women and for subjects in the comb...

The core methods in today's econometric toolkit are linear regression for statistical control, instrumental variables methods for the analysis of natural experiments, and differences-in-differences methods that exploit policy changes. In the modern experimentalist paradigm, these techniques address clear causal questions such as: Do smaller classes...

The veterans disability compensation (VDC) program, which provides a monthly stipend to disabled veterans, is the third largest American disability insurance program. Since the late 1990s, VDC growth has been driven primarily by an increase in claims from Vietnam veterans, raising concerns about costs as well as health. We use the draft lottery to...

We use student assignment lotteries to estimate the effect of charter school attendance on student achievement in Boston. We also evaluate a related alternative, Boston's pilot schools. Pilot schools have some of the independence of charter schools, but operate within the Boston Public School district and are covered by some collective bargaining p...

Military service reduces civilian labor market experience but subsidizes higher education through the GI Bill. Both of these channels are likely to affect civilian earnings. New estimates of the effects of military service using Vietnam-era draft-lottery instruments show post-service earnings effects close to zero in 2000, in contrast with earlier...

In the past century, more people have perished from famine than from both world wars combined. Yet we know little about why the intensity of famines can vary so much geo-graphically or what the long run e¤ects of exposure are to survivors. This paper addresses both of these questions in the context of China's Great Famine. We …rst show a novel sour...

We study the consequences of an exogenous upsurge in coca prices and cultivation in Colombia, where most coca leaf is now harvested. This shift generated only modest economic gains in rural areas, primarily in the form of increased self-employment earnings and increased labor supply by teenage boys. The rural areas that saw accelerated coca product...

Between 1898 and 1948, English was the language of instruction for most post-primary grades in Puerto Rican public schools. Since 1949, the language of instruction in all grades has been Spanish. We use this policy change to estimate the effect of English-intensive instruction on the English-language skills of Puerto Ricans. Although naive estimate...

The term ‘treatment effect’ refers to the causal effect of a binary (0–1) variable on an outcome variable of scientific or policy interest. Economics examples include the effects of government programmes and policies, such as those that subsidize training for disadvantaged workers, and the effects of individual choices like college attendance. The...

We develop semiparametric tests for conditional independence in time series models of causal effects. Our approach is motivated by empirical studies of monetary policy effects. Our approach is semiparametric in the sense that we model the process determining the distribution of treatment the policy propensity score but leave the model for outcomes...

Many North American college students have trouble satisfying degree requirements in a timely manner. This paper reports on a randomized field experiment involving two strategies designed to improve academic performance among entering full-time undergraduates at a large Canadian university. One treatment group (services) was offered peer advising an...

This paper uses the 2000 Census 1-in-6 sample to look at the long-term impact of Vietnam-era military service. Instrumental Variables estimates using draft-lottery instruments show post-service earnings losses close to zero in 2000, in contrast with earlier results showing substantial earnings losses for white veterans in the 1970s and 1980s. The e...

Instrumental variables (IV) estimates using the draft lottery show that white Vietnam-era draftees suffered substantial post-service earnings losses in the 1970s and 1980s. Angrist (1990) explains these losses as due primarily to lost labor market experience. Non-public use data fromthe 2000 Census allow the first longerterm follow-up for a large s...

High rates of attrition, delayed completion, and poor achievement are growing concerns at colleges and universities in North America. This paper reports on a randomized field experiment involving two strategies designed to improve these outcomes among first-year undergraduates at a large Canadian university. One treatment group was offered peer adv...

This paper presents evidence on the child-quantity/child-quality trade-off using quasi-experimental variation due to twin births and preferences for a mixed sibling-sex composition, as well as ethnic differences in the effects of these variables. Our sample includes groups with very high fertility. An innovation in our econometric approach is the j...

A longstanding question in the economics of the family is the relationship between sibship size and subsequent human capital formation and economic welfare. If there is a causal quantity-quality tradeoff, then policies that discourage large families should lead to increased human capital, higher earnings, and, at the macro level, promote economic d...

Colombia's PACES program provided over 125,000 poor children with vouchers that covered the cost of private secondary school. The vouchers were renewable annually conditional on adequate academic progress. Since many vouchers were assigned by lottery, program effects can reliably be assessed by comparing lottery winners and losers. Estimates using...

Este artículo presenta una discusión entre economistas de primera línea acerca de cómo realizar investigación empírica en economía. Los participantes presentan los motivos que les llevan a elegir un proyecto, la construcción de bases de datos, los métodos que emplean, el papel de la teoría y su visión sobre los principales enfoques empíricos altern...

Quantile regression (QR) fits a linear model for conditional quantiles just as ordinary least squares (OLS) fits a linear model for conditional means. An attractive feature of OLS is that it gives the minimum mean-squared error linear approximation to the conditional expectation function even when the linear model is misspecified. Empirical researc...

Theory and evidence concerning the functioning of the labor market. Particular emphasis on the roles played by government and institutions. Topics include minimum wages, labor market effects of social insurance and welfare programs, the collective bargaining relationship, discrimination, human capital, and unemployment. From the course home page: C...