Nano Barahona
Job Market Candidate

Stanford University
Department of Economics
579 Jane Stanford Way
Stanford, CA 94305

(650) 532-4564

Curriculum Vitae

Primary Field:
Industrial Organization

Secondary Field:
Public Economics

Expected Graduation Date:
June, 2021

Dissertation Committee:

Matthew Gentzkow (Primary):

Liran Einav:

Rebecca Diamond:

Pascaline Dupas:

Job Market Paper

Equilibrium Effects of Food Labeling Policies
with Cristóbal Otero, Sebastián Otero and Joshua Kim
Warning labels on unhealthy food products are an increasingly common policy tool to combat obesity. Although informing consumers usually improves their welfare, supply-side responses can either offset or amplify the positive effects of food labels. This paper studies the equilibrium effects of a regulation in Chile that mandates the use of warning labels on products whose sugar or calorie concentration exceeds certain thresholds. Using scanner data from Walmart, we find an overall decrease in sugar and calorie intake of 9% and 7% after the policy. To reveal mechanisms, we zoom in on the breakfast cereal market. On the demand side, we show that consumers substitute from labeled to unlabeled products. This effect is mostly driven by products which, according to survey-based evidence, consumers mistakenly believed to be healthy. On the supply side, we find substantial reformulation of products and bunching just below the regulatory thresholds. We develop and estimate a model of supply and demand for food and nutrients. Consumers care about products' price, taste, and nutritional content but have poorly calibrated beliefs about nutrition. Firms choose products' prices and nutritional content to maximize profits. We find that food labels increase consumer surplus by 3.6% of total expenditure. These effects are enhanced by firms' responses. We then use the model to study alternative policy designs. Under optimal policy thresholds, food labels cause gains in average consumer surplus similar to those of optimal sugar taxes but benefit the poor relatively more.


Vintage-Specific Driving Restrictions
Review of Economic Studies, Volume 87, Issue 4, July 2020, Pages 1646-1682
Local air pollution has led authorities in many cities around the world to impose limits on car use by means of driving restrictions or license-plate bans. By placing uniform restrictions on all cars, many of these programs have created incentives for drivers to buy additional, more polluting cars. We study vintage-specific restrictions, which place heavy limits on older, polluting vehicles and no limits on newer, cleaner ones. We use a novel model of the car market and results from Santiago's 1992 program, the earliest program to use vintage-specific restrictions, to show that such restrictions should be designed to work exclusively through the extensive margin (type of car driven), never through the intensive margin (number of miles driven). If so, vintage restrictions can yield important welfare gains by moving the fleet composition toward cleaner cars, comparing well to alternative instruments such as scrappage subsidies and pollution-based registration fees.

Work in Progress

Affirmative Action in Centralized College Admission Systems
with Cauê Dobbin and Sebastián Otero · [Preliminary draft available upon request]
We study the distributional consequences of affirmative action in selective college education in the context of a centralized admission system. We examine the effects of a law passed in Brazil in 2012 mandating all federal public universities to increase the number of seats reserved for public high-school students to half of the total. We show that the share of admits in public universities coming from public high schools increased from 45% in 2011 to 65% in 2016. To study the overall distributional consequences of the policy, we estimate a discrete choice model and use the rules from the centralized admission system to simulate a counterfactual allocation of spots in a regime without affirmative action. We use exogenous variation based on the degree-specific admission thresholds to construct selection-corrected estimates of treatment effects on test scores and graduation rates of beneficiaries and displaced individuals.

Financial Aid, and the Supply and Demand for Higher Education
We study the equilibrium effects of government student loans on college access. Student loans are widely used by governments to promote access to higher education. However, the net increase in access can be substantially smaller than the number of beneficiaries, for at least two reasons. First, some of the beneficiaries would still attend to college by otherwise paying tuition out-of-pocket. Second, institutions may raise tuition or reduce privately supplied student aid. We exploit a drastic contraction in the Brazilian student loan program to show that private institutions responded to the contraction by reducing tuition and offering additional scholarships. Our results suggest that 65% of loan beneficiaries would enroll in the same degree in the absence of federal loans. We then develop a model of supply and demand for higher education and show how governments can optimally design loans in order to promote fair access at a lower fiscal cost.

External and Internal Instruments in Structural Estimation
We consider the choice of instrumental variables when a structural model may potentially be misspecified. We contrast internal instruments, which have a direct causal effect on the outcome independent of the endogenous variable of interest, with external instruments, which do not. We show conditions under which the researcher's estimand maintains a causal interpretation under external instruments but not under internal instruments. We apply our framework to estimation of differentiated goods demand models under price endogeneity and estimation of production function parameters with transmission bias. We illustrate our findings, and some extensions, with numerical simulations.