Publications
The Cost-effectiveness of Clean Cookstove Carbon Mitigation after Adjusting for Additionality and Impact
Climate Change Economics, 2026, vol. 17 (4) (with Susanna Berkouwer)
Abstract: More than 200 million people cook with charcoal daily. This has high climate costs: a Kenyan household using a charcoal stove emits as much CO per year as an average U.S. household using a gasoline vehicle. However, concerns around additionality (do subsidies increase sales?) and impact (do sales reduce emissions?) undermine the clean cooking transition. We conduct a randomized trial with 955 households in Nairobi to quantify the additionality and impact of subsidies for an improved cookstove in use by millions of households. Factoring in that 16% of total subsidy spending flows to nonadditional participants, incentivizing one additional stove sale requires US$32 in subsidy spending. Three-and-a-half years later, 83% of buyers own a working improved stove and 11% of nonbuyers do. Factoring in control group adoption and breakage rates, each additional stove generates at least 2.8 additional years of working improved stove ownership. Despite widespread stacking, stove ownership on average abates 1.7 tCO per year. Together, the subsidies abate CO at US$7 per ton (estimates range between US$3.5 and US$8.1). Each dollar of cookstove subsidy abates 168–383 times more CO than a dollar of electric vehicle subsidy.
Cooking, Health, and Daily Exposure to Pollution Spikes
American Economic Journal: Economic Policy, May 2026, vol. 18 (2), pp. 511-47 (with Susanna Berkouwer)
Abstract: Many routine daily activities—such as cooking and commuting—cause large recurring pollution spikes that may impact health without significantly affecting average exposure. We study pollution spikes by combining experimental variation in cooking technology with high-frequency data on individual pollution exposure and time-use in Kenya. Improved cookstoves reduce PM2.5 spikes while cooking by 52µg/m3 (42%) and cause a 0.24 standard deviation reduction in self-reported respiratory symptoms. However, even after more than three years of daily use, we find no clinical health improvements; possibly because we detect no impact on average exposure. Clinical health improvements may require reductions in ambient concentrations.
Noise, Cognitive Function, and Worker Productivity
American Economic Journal: Applied Economics, October 2024, vol. 16 (4), pp. 322-360.
Abstract: Cognitive science research suggests the noisy workplaces common in low and middle income countries can impair workers’ cognitive functions. However, whether this translates into lower earnings for workers depends on the importance of these functions for productivity and whether workers understand these effects. I use two randomized experiments in Nairobi, Kenya to answer these questions. First, I randomize exposure to engine noise during a textile training course at a government training facility. An increase of 7 dB reduces productivity by approximately 3%. In order to study what mechanism drives this effect, I then randomize engine noise during tests of cognitive function and an effort task. The same noise change impairs cognitive function but not effort task performance. Finally, in both experiments, I examine whether individuals appreciate the impact of noise on their performance by eliciting participants’ willingness to pay for quiet working conditions while randomly varying whether they are compensated based on their performance. Individuals’ willingness to pay does not depend on the wage structure; suggesting that they are not aware that quiet working conditions would increase their performance pay. Thus, workers may fail to mitigate earnings losses by sorting into quieter jobs where they are more productive.
Credit, Attention, and Externalities in the Adoption of Energy Efficient Technologies by Low-income Households
American Economic Review, October 2022, vol. 112 (10), pp. 3291-3330. (with Susanna B. Berkouwer)
Abstract: We study an energy efficient charcoal cookstove in an experiment with 1,000 households in Nairobi. We estimate a 39% reduction in charcoal spending, which matches engineering estimates, generating a 295% annual return. Despite fuel savings of $237 over the stove’s two-year lifespan—and $295 in emissions reductions—households are only willing to pay $12. Drawing attention to energy savings does not increase demand. However, a loan more than doubles WTP: credit constraints prevent adoption of privately optimal technologies. Energy efficient technologies could drive sustainable development by slowing greenhouse emissions while saving households money.
Changing Family Attitudes to Promote Female Employment
AEA Papers and Proceedings, May 2019, vol. 109, pp. 138-142. (with Seema Jayachandran)
Abstract: India’s female employment rate is one of the lowest in the world. One approach to expanding female employment is to make young women’s family members more supportive of them working. We report on the effects of two interventions aimed at increasing family members’ supportiveness in rural India. The first entails showing them video testimonials by working women and their family members. The second prompts a conversation between working women and their families about the benefits and challenges they face when a woman in the household works. We find no evidence that the interventions changed employment or attitudes.
Cognitive Science in the Field: A Preschool Intervention Durably Enhances Intuitive but not Formal Mathematics
Science, 7 July 2017, vol. 375 (6346), pp. 47-55. (with Moira R. Dillon, Harini Kannan, Elizabeth S. Spelke and Esther Duflo)
Abstract: Many poor children are underprepared for demanding primary school curricula. Research in cognitive science suggests that school achievement could be improved by preschool pedagogy in which numerate adults engage children’s spontaneous, nonsymbolic mathematical concepts. To test this suggestion, we designed and evaluated a game-based preschool curriculum intended to exercise children’s emerging skills in number and geometry. In a randomized field experiment with 1540 children (average age 4.9 years) in 214 Indian preschools, 4 months of math game play yielded marked and enduring improvement on the exercised intuitive abilities, relative to no-treatment and active control conditions. Math-trained children also showed immediate gains on symbolic mathematical skills but displayed no advantage in subsequent learning of the language and concepts of school mathematics.
Working Papers
The Effect of Exposure: Evidence from Spatial Choices in Nairobi (with Gabriel Kreindler and Oluchi Mbonu)
Abstract: How much do people dislike opportunities they have never been exposed to, and why? We study how exposure affects work location decisions of casual workers. We offer short-term employment and randomize training locations to induce novel exposures. Participants sacrifice 22% of the median daily wage to avoid working in a location never visited before; one hour-long visit eliminates this premium. Workers anticipate two thirds of the effect exposure has on their later preferences. Results are most consistent with perceived fixed costs of exposure rather than sorting or quality uncertainty. Unfamiliar neighborhoods are also less likely to enter workers’ consideration sets.
Green Subsidies with Demand Distortions (with Susanna Berkouwer)
Abstract: Standard Pigouvian theory predicts that externalities should be corrected at the margin. However, demand distortions such as credit constraints or behavioral biases create a wedge between marginal benefit and marginal cost. While these distortions can lower aggregate abatement, they can increase the efficiency of green subsidy spending. In theory, this happens through two channels: by shifting the marginal adopter toward higher private and social benefits, and by increasing demand elasticity. We test these predictions by cross-randomizing fixed cost subsidies, marginal cost subsidies, and loan access for an induction stove among 2,134 charcoal users in Kenya. Marginal cost subsidies that lower electricity costs by up to 75% have a precise zero effect on both adoption and usage among both the more and less distorted groups. However, credit constraints increase the observable welfare benefit per fixed cost subsidy dollar from US$6.1 to US$11 and lower the subsidy cost of abatement from US$22 to US$13 per tCO2e. Distortions operate through the two hypothesized channels: credit constraints increase the marginal positive externality by 19% and the marginal fuel savings by 30%, and lower the subsidy cost per marginal adoption by 30%. We estimate the model to generate counterfactual simulations and find that each subsidy dollar generates 14 times more observable welfare benefit in the observed, distorted context than in a counterfactual context with no distortions: in this counterfactual, the subsidy cost of abatement increases more than tenfold to US$137 per tCO2e. Contexts with larger demand distortions could generate some of the most efficient abatement opportunities.
Measuring Gender Attitudes Toward Men and Women (with Christine Exley, Heather Sarsons, and Muriel Niederle)
Abstract: Surveys of gender attitudes typically ask respondents to evaluate statements about men’s or women’s behaviors in isolation, without eliciting how the same behavior is evaluated when assigned to the other gender. As a result, responses to standard statements cannot assess whether respondents perceive society as holding gender-neutral views across men and women. We introduce paired (role-reversed) elicitation, which varies the gender assigned to otherwise identical behaviors. In a representative sample of Americans, responses to standard statements suggest that few respondents perceive society as holding traditional views toward women. The paired elicitation, however, reveals a gender-neutrality gap: only about half of respondents report the same beliefs across the standard and role-reversed statements, even though these statements only vary in terms of which gender is assigned to which behavior. Paired responses also uncover substantial heterogeneity and reveal broader underlying beliefs driving responses, such as beliefs about work and family rather than gender-specific views.
Gender Views: A Restricted Path for Men and A Mission Impossible for Women (with Christine Exley, David Klinowski, Muriel Niederle, and Heather Sarsons)
Abstract: This paper comprehensively investigates how people expect labor market behaviors by men and by women to be viewed. Men conforming to the stereotypical male behavior—to be confident, to be assertive, to be ambitious, to be competitive, to be leaders, to take risks, to negotiate, and to self-promote—are expected to be praised and not criticized. Since the opposite is expected for men not conforming to the male stereotype, we say that men face a “restricted path.” We instead say women face a mission impossible because there is no behavior for women that is expected to secure praise and avoid criticism. Any behavior women pursue is also less likely to secure praise than men who conform to the male stereotype. Additional results investigate whether evidence for men’s restricted path and women’s mission impossible differs when we ask about the expected views of groups that vary in gender, age, race, political identity, education, and profession. Additional results also reveal that—for prosocial traits—no mission impossible arises for either gender; being prosocial is expected to be praised and not criticized
Scaling Cognitive Science with Classroom Games for Learning Mathematics (with Moria R. Dillon, Esther Duflo, Harini Kannan and Elizabeth S. Spelke) Revise and Resubmit at Nature Human Behaviour
Abstract: We report two randomized evaluations of educational interventions targeting children in low-income neighborhoods of Delhi, India. Four math games, played in social groups, associated early emerging and universally intuitive concepts of number and geometry with the mathematical language, symbols, and operations taught in Delhi government schools. The first experiment, conducted in 231 NGO-run preschool classrooms (1,986 children) showed that the games enhanced children’s mastery of mathematics both immediately after the intervention and a year later, after children’s first year of primary school. The second experiment, conducted in 141 kindergarten and first-grade classrooms in government schools (2,828 children), with no extra personnel, showed that the games remained effective when played cooperatively by larger groups of children, led by their regular teachers, during time allotted for math instruction. These experiments show how insights from basic research on children’s mathematical intuitions can be leveraged to design ready-to-scale interventions for the foundational years.
Attending Kindergarten Improves Cognitive Development in India, but All Kindergartens Are Not Equal (with Seema Jayachandran)
Abstract: Early childhood is a critical period for child development, and several studies find high returns to formal early schooling (e.g., pre-K) in developed countries. However, there is limited evidence on whether formal pre-primary schooling is an effective model in developing countries. We study the impacts of attending kindergarten on child development in Karnataka, India, through a randomized evaluation. We partnered with a private kindergarten provider to offer two-year scholarships to children in low-income families. Children who attend the partner kindergarten due to the scholarship experience a 0.8 standard deviation gain in cognitive development. Some children induced to attend the partner kindergarten would not have attended kindergarten, while others would have attended a different kindergarten. We use machine learning techniques to predict each child’s counterfactual activity and then estimate separate treatment effects for each type of switcher. We find that the short-run effect on cognition is driven mostly by children who would have otherwise not attended kindergarten. About 40% of the effect on cognitive development persists through first grade, with more persistence for higher-order thinking skills. In contrast, we find no effects on socioemotional development, which could be due to most children interacting with other children in daycare centers even if they do not attend kindergarten.
Works in Progress
Morality in Consumption Decisions and the Global Cost of Climate Change Mitigation (with Susanna Berkouwer)