Working Papers

A Rosetta Stone for Human Capital
(with Justin Sandefur)
Abstract
Comparing human capital across different measures is a central challenge in many empirical economics settings, from quantifying local schools' contribution to neighborhood effects to understanding the causes and consequences of global education gaps. Leveraging insights from item response theory with simple data collection, we develop a new methodology to non-parametrically translate performance measured across arbitrarily different scales. We implement this approach to link four of the world's largest standardized tests using a hybrid exam we developed and administered to students in India and the United States. Armed with this learning "Rosetta Stone", we apply our translations out of sample to microdata from 600,000 pupils across 80 countries and match their socio-economic status to moments of the global income distribution, establishing four new facts: (i) students with the same household income score significantly higher if they live in richer countries; (ii) the income-test score gradient is steeper in countries with greater income inequality; (iii) girls read better than boys at all incomes but only outperform them in mathematics at the lowest deciles of the global income distribution, and (iv) the test-score gap between public and private schools increases with inequality, partially due to a rise in socio-economic sorting across school types.
| PDF | Coverage
The Economist

Environmental Beliefs and Adaptation to Climate Change
Abstract
Effective climate adaptation relies on accurate perceptions of the local environment. Bangladeshi rice farmers, for instance, must learn about their soil's salinity to choose the appropriate seed. Farmers cannot directly observe salt levels and therefore form beliefs based on downstream indicators of salinity, such as their plant's health and overall yield. Signals of this type present obstacles for learning due to their ambiguity: while low yield could suggest elevated salt, for instance, that same sign also matches a host of other potential explanations for dampened agricultural productivity. Bayesian farmers therefore endogenously process data in line with their priors, e.g., someone worried about high salinity will interpret the ambiguous sign of reduced harvest as an indicator of too much salt over other threats. I document this pattern empirically comparing two natural experiments that while equally impacting true salinity as measured by agronomic sensors, differentially shift farmers' priors about salinity, altering their interpretation of subsequent signals, and ultimately leading to different beliefs. I conduct field experiments to validate the importance of these environmental expectations for technology adoption and agricultural profits.
| PDF | Survey Instruments
Baseline (English) | Baseline (Bangla) | Endline (English) | Endline (Bangla) | Dec. 2023 Follow-Up (English) | Dec. 2023 Follow-Up (Bangla)
| Coverage
World Bank Blog | VoxDev Podcast

Floods
[Online Interactive Guide: How to Measure Floods from Space]
Abstract
Floods threaten a quarter of the world's population, most of whom live in poor countries. How do floods impact economic development, and how do households adapt? To answer these questions, I first combine methods from geophysics and machine learning in the analysis of satellite data to detect inundation at a granular geographic level anywhere every day for the past two decades. Using this approach in Bangladesh, I find that floods cause a persistent decline in economic activity and force structural change by pushing employment out of agriculture, spurring migration, and shifting children into school. Places with recent exposure to floods experience less harm after subsequent inundation. Using a simple model of experience-driven adaptation, I derive empirical tests for two mechanisms underpinning this pattern and find evidence for both. In a survey of rural farmers, I first show that past flood exposure increases the perceived marginal benefit of adaptation investment by raising households' beliefs about future disaster risk and damages. I next find that the marginal cost of coping with floods via temporary urban migration declines in inundation experience. Consistent with this "learning-by-doing" channel, reduced mobility frictions identified from quasi-random variation in Colonial-era transportation networks mediate the differential treatment effects of past flood exposure. Together, my results indicate that endogenous adaptation will significantly reduce the damage from future flooding.
| PDF | Coverage
VoxDev Podcast

What Jobs Come to Mind? Stereotypes About Fields of Study
(with John J. Conlon)
Abstract
We test for stereotyping—the exaggeration of distinctive traits—in a high-stakes economic environment. Using both large-scale nationally representative data and surveys administered among undergraduates at the Ohio State University, we measure how US freshmen perceive the relationship between college majors and occupations. We show that students stereotype fields of study, greatly overestimating the likelihood that majors lead to their distinctive jobs (e.g., counselor for psychology, journalist for journalism). Using an implicit association test, we show that students associate majors with their distinctive careers and that these associations strongly predict belief biases, in line with a stereotyping mechanism. A simple equilibrium model of the labor market predicts that stereotyping reduces welfare costs by increasing misallocation, which suggestive evidence on job/major mismatch corroborates. In a field experiment, we test a light-touch policy to reduce stereotyping and find significant effects on students' intentions about what to study as well as the classes and majors in which they enroll.
| PDF | Survey Instruments
Main Survey Instruments | Information Module (Qualtrics Link with Hypothetical Responses) | IAT and Supplemental Surveys (with Qualtrics Link) | Coverage
Econimate Video Summary

Publications

Texts Don't Nudge: An Adaptive Trial to Prevent the Spread of COVID-19 in India
(with Girija Bahety, Sebastian Bauhoff, and James Potter)
Journal of Development Economics, 2021
Abstract
We conduct an adaptive randomized controlled trial to evaluate the impact of a SMS-based information campaign on the adoption of social distancing and handwashing in rural Bihar, India, six months into the COVID-19 pandemic. We test 10 arms that vary in delivery timing and message framing, changing content to highlight gains or losses for either one's own family or community. We identify the optimal treatment separately for each targeted behavior by adaptively allocating shares across arms over 10 experimental rounds using exploration sampling. Based on phone surveys with nearly 4,000 households and using several elicitation methods, we do not find evidence of impact on knowledge or adoption of preventive health behavior, and our confidence intervals cannot rule out positive effects as large as 5.5 percentage points, or 16%. Our results suggest that SMS-based information campaigns may have limited efficacy after the initial phase of a pandemic.
| PDF | Survey Instrument & Replication Materials

The New Era of Unconditional Convergence
(with Arvind Subramanian and Justin Sandefur)
Journal of Development Economics, 2021
Abstract
The central fact that has motivated the empirics of economic growth—namely unconditional divergence—is no longer true and has not been so for decades. Across a range of data sources, poorer countries have in fact been catching up with richer ones, albeit slowly, since the mid-1990s. This new era of convergence does not stem primarily from growth moderation in the rich world but rather from accelerating growth in the developing world, which has simultaneously become remarkably less volatile and more persistent. Debates about a "middle-income trap" also appear anachronistic: middle-income countries have exhibited higher growth rates than all others since the mid-1980s.
| PDF | Replication Materials
Replication Data and Code | Figures from the Paper
| Coverage
Bloomberg (Noah Smith) | The Economist | The New York Times (Paul Krugman) | The Wall Street Journal

Other Writing

A Requiem for Hyperglobalization
(with Arvind Subramanian and Justin Sandefur)
Foreign Affairs, June 12, 2024

Resources

Teaching
Syllabus for my 2021 course on the economics of gender inequality
PDF

Survey Instruments
Bangladesh Farmer Surveys
Baseline (English) | Baseline (Bangla) | Endline (English) | Endline (Bangla) | Dec. 2023 Follow-Up (English) | Dec. 2023 Follow-Up (Bangla)

Covid-19 SMS Survey
Qualitative Survey Instrument | Main Survey Instrument

College Major Stereotypes Surveys
Main Survey Instruments | Information Module (Qualtrics Link with Hypothetical Responses) | IAT and Supplemental Surveys (with Qualtrics Link)

Bangladesh Labor Force Survey 2016-17
Roshni Islam translated the 2016-17 questionnaire to English. The underlying data can be acquired by contacting the Bangladesh Bureau of Statistics. For more details, visit this link.

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