Research

“Mandatory Minimum Sentencing and its Effect on Sentencing Distributions: Evidence from Canada,” (with Emilia Galan and Steven Lehrer). Canadian Journal of Economics, forthcoming.

Whether judges and prosecutors should be given full discretionary power in sentencing or mandatory minimum sentences be imposed remains a fiercely debated topic. In this paper, we examine the impact of Canada's 2005 introduction of minimum sentences on sexual offences against children and child pornography on the distribution of sentence lengths using administrative data containing the universe of these offences that occurred between 2003 and 2007. We find that the average sentence length for affected crimes at times increased by substantially more than the newly imposed minimum, and effects of the policy appear even in the middle and upper portions of the sentencing distribution. These increases occur immediately following the policy change, signalling that judges and prosecutors quickly change their sentencing behaviour after the implementation of mandatory minimum sentences. These lengthier sentences have significant implications for the estimation of the fiscal costs of minimum sentencing policies.

“Focused Interventions and Test Score Fade-out,” (with Michael Gilraine). Review of Economics and Statistics, forthcoming.

An administrative rule in North Carolina allowed students who failed an exam to retake it approximately two weeks later, triggering a brief yet intense test preparation period. We develop a structural model that accounts for selection and find that these students score much higher on the retest. Using a regression discontinuity design, we find substantial fade-out of the test score gains after one year but some persistence thereafter. Unlike other interventions that produce similar initial increases in performance, we do not observe benefits to long-term outcomes. Our findings highlight that persistence should be accounted for when comparing educational interventions.

“Same race teachers don't necessarily raise academic achievement,” Economics Letters, vol. 223, 110993 (February 2023).

Numerous studies have found that students who are of the same race as their teacher experience increased academic achievement. In this paper, I attempt to explain when these benefits occur and which students are most likely to achieve the largest gains. Using exogenous variation in student-teacher matches and classroom composition from Tennessee's Project STAR experiment, I find that below average achieving students benefit most from having a teacher of the same race, but the benefits from matching can be substantially reduced in smaller classes. Moreover, the effect is decreased in racially homogeneous classes where the teacher is the majority race.

“Cautions when normalizing the dependent variable in a regression as a z-score,” Economic Inquiry, vol. 61(2): 402-412 (April 2023).

It is common in empirical analysis to facilitate inference by transforming the dependent variable to follow a standard normal distribution. In this paper, I show that using this transformation results in the estimated treatment effects being systematically attenuated towards zero and bounded in magnitude. The level of attenuation can be empirically relevant. I propose an alternative normalization wherein the dependent variable is divided by the square root of its within variation, which corrects these issues. I show that, in a simple linear regression, the method produces an estimated treatment effect that is numerically identical to Cohen's d.

“Penalties for Speeding and their Effect of Moving Violations: Evidence from Quebec Drivers,” (with Vincent Chandler and Lealand Morin). Canadian Journal of Economics, vol. 56(1): 225-246 (February 2023).

In 2008, the province of Quebec drastically increased penalties for speeding well above the speed limit by doubling fines and instituting on-the-spot licence suspension. Using administrative driving and licensing records in Quebec from 2006 to 2010, we examine whether the new law discouraged unlawful driving behaviour by investigating the frequency with which motorists received traffic citations. We find that the new law was effective in deterring motorists from speeding. Moreover, the effect was most pronounced for males compared to females, for young compared to old, and especially so for drivers with high demerit point balances accumulated from past infractions compared to those with few or no tickets. In sum, the change in behaviour was most apparent for those drivers who were the intended targets for the legislation.

“Scholarships and student effort: Evidence from Colombia's Ser Pilo Paga program,” (with Gloria L. Bernal). Economics of Education Review, vol. 72: 121-130 (October 2019).

Launched in 2014, Colombia's Ser Pilo Paga program aimed to increase college enrollment for low income students by providing 10,000 means-tested scholarships annually to the highest performers on the country's high school exit exam. We theorize that the introduction of the scholarship incentivized these students to better prepare for this exam. Exploiting the SES thresholds for eligibility using a regression discontinuity design, we find that students who qualify for the scholarship score about 0.09 test score standard deviations higher than those who do not. We also find that the program increased the representation of the poorest students in the top 9% of test takers. Survey evidence suggests that students spent more time and money preparing for the test.

“Dynamic Treatment Effects of Teacher’s Aides in an Experiment with Multiple Randomizations,” Economic Inquiry, vol. 56(2): 1244-1260 (April 2018).

Using data from a large scale two-stage experiment wherein students and teachers were randomized at both kindergarten entry and first grade to be sorted into classes either with or without full-time teacher's aides, I estimate an econometric model that is uniquely suited to take advantage of this design to determine their effect on academic achievement. The identification strategy produces fully nonparametric dynamic average treatment effects for every treatment path. I find that the use of full-time teacher's aides increases student achievement, but the benefits appear to accrue mostly to those of higher socioeconomic status and to white students. A cost-benefit analysis shows that full-time teacher's aides may be a competitive alternative to class size reductions in terms of net social benefits.

“A Self-Reference Problem in Test Score Normalization,” Economics of Education Review, vol. 61: 79-84 (December 2017).

It is considered standard practice to transform IRT-scaled test scores into standard normal variables for regression analysis in order to enable comparison with other research whose test scores are similarly transformed. This paper calls this practice into question. I show that these transformations can potentially result in radically different estimates of regression parameters due to differences in sample composition. Regression coefficient comparisons between different samples that use z-standardized test scores is only possible if the samples are considered to be random draws from the same population. I outline several different methods to deal with this problem and the caveats attached to each.

“Test Score Measurement and the Black-White Test Score Gap,” Review of Economics and Statistics, vol. 99 (4): p. 652-656 (October 2017).

Research as to the size of the Black-White test score gap often comes to contradictory conclusions. Recent literature has affirmed that the source of these contradictions and other controversies in education economics may be due to the fact that test scores contain only ordinal information. In this paper, I propose a normalization of test scores that is invariant to monotonic transformations. Under fairly weak assumptions, this metric has interval properties and thus solves the ordinality problem. The measure can serve as a valuable robustness check to ensure that any results are not simply statistical artifacts from the choice of scale.

“Racial Interaction Effects and Student Achievement,” Education Finance and Policy, vol. 12 (4): p. 447-467 (Fall 2017).

Previous research has found that students who are of the same race as their teacher tend to perform better academically. This paper examines the possibility that both dosage and timing matters for these racial complementarities. Using a model of education production that explicitly accounts for past observable inputs, a conditional differences-in-differences estimation procedure is employed to nonparametrically identify dynamic treatment effects of various sequences of interventions. Applying the methodology to Tennessee's Project STAR class size experiment, I find that racial complementarities may vary considerably according to treatment path. Early exposures to same-race teachers yield benefits that persist in the medium run. This same-race matching effect may explain a non-trivial portion of the Black-White test score gap.

“Hypothesis Testing for Arbitrary Bounds,” Economics Letters, vol. 121 (3): p. 492-494 (December 2013).

I derive a rigorous method to help determine whether a true parameter takes a value between two arbitrarily chosen points for a given level of confidence via a multiple testing procedure which strongly controls the familywise error rate. For any test size, the distance between the upper and lower bounds can be made smaller than that created by a confidence interval. The procedure is more powerful than other multiple testing methods that test the same hypothesis. This test can be used to provide an affirmative answer about the existence of a negligible effect.

Please see Curriculum Vitae for a list of selected working papers.