Esther Caroline Duflo was born on 25 October 1972 in Paris, the daughter of a pediatrician, Violaine Duflo, and a mathematics professor, Michel Duflo. She grew up in Asnières, a western suburb of Paris, and attended local public schools before finishing secondary education at the Lycée Henri-IV. Early exposure to her mother’s medical work and to the wider world of social questions left her interested in the conditions of children’s lives, an interest that later hardened into a professional focus on poverty. She entered the École Normale Supérieure, where she studied history and economics, and received a master’s degree in economics in 1995 from DELTA, the Paris research grouping that later became part of the Paris School of Economics. A year spent in Russia, including work as a research assistant connected to Jeffrey Sachs’s advisory role during post-Soviet reform, sharpened her sense that large economic transitions were poorly understood from the ground up.
She arrived at the Massachusetts Institute of Technology in 1995 as a doctoral student. Development economics was then still dominated by cross-country regressions and broad theories of growth. In the classroom of Abhijit Banerjee and Michael Kremer she encountered a different habit of mind: ask what the ideal experiment would be, then design the closest feasible comparison. Her dissertation, supervised jointly by Banerjee and Joshua Angrist, used a large Indonesian school-construction program as a natural experiment. Children who were young enough to benefit from the new schools obtained more education and later earned higher wages, giving early causal evidence that schooling returns were real in a low-income setting. She received her Ph.D. in 1999 and joined the MIT faculty immediately.
The decisive institutional step came in 2003. With Banerjee and Sendhil Mullainathan she founded the Poverty Action Lab at MIT, later renamed the Abdul Latif Jameel Poverty Action Lab, or J-PAL, after an endowment from Mohammed Abdul Latif Jameel. Rachel Glennerster became its first executive director and gave the organization a clear mission: reduce poverty by ensuring that policy is informed by scientific evidence, through research, policy outreach, and training. The method at the center was the randomized controlled trial. Rather than debating whether aid worked in the abstract, researchers would test specific interventions—extra teachers, deworming pills, small incentives, information campaigns—by assigning them at random to some communities, schools, or households and not to others, then measuring the difference.
The resulting studies accumulated into a practical map of what poor households actually do and why. In Rajasthan, immunization rates were low partly because clinics were unreliable and a parent lost a day’s wages if the nurse was absent. When mobile clinics made the service dependable and families received a small bag of lentils, vaccination rates rose several-fold. In Indian cities, remedial tutoring and computer-assisted learning produced large short- and medium-term gains in test scores, suggesting that the curriculum was often aimed above the level of many students. In Kenya, reducing class size with permanently employed teachers did little, while short-term contracts renewed only for effective teachers improved learning. Work on microcredit found that small loans helped some entrepreneurs expand but did not, on average, transform household poverty. Studies of fertilizer, bed nets, and savings products repeatedly showed that small changes in price, timing, or default rules could shift behavior more than abstract appeals to rationality. The point was not that the poor are irrational, but that their decisions are constrained by scarce attention, unreliable institutions, and thin margins.
Duflo and Banerjee synthesized fifteen years of this work in Poor Economics, published in 2011. The book rejected both the grand optimism that foreign aid would reliably produce growth and the grand pessimism that nothing external could help. It argued instead for a patient, piecemeal approach: identify binding constraints, test remedies, and scale what survives evaluation. Good Economics for Hard Times, published in 2019, extended the same empirical temper to migration, trade, climate, and social policy in rich countries. Duflo has also written a children’s book, Poor Economics for Kids, and holds a chair at the Collège de France.
Recognition arrived early and then at the highest level. She received the Elaine Bennett Research Prize, the Prix du meilleur jeune économiste de France, a MacArthur Fellowship in 2009, and the John Bates Clark Medal in 2010, awarded to the American economist under forty judged to have made the most significant contribution. In 2019 the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel went jointly to Duflo, Banerjee, and Kremer “for their experimental approach to alleviating global poverty.” She was the youngest laureate in the prize’s history and only the second woman to receive it. By the time of the award, J-PAL affiliates had run hundreds of evaluations across dozens of countries, and programs shaped by those evaluations had reached hundreds of millions of people.
She became a United States citizen in 2012 while remaining French. She and Banerjee, her longtime collaborator, married in 2015; they have two children. Professionally she has continued as co-director of J-PAL and as the Abdul Latif Jameel Professor of Poverty Alleviation and Development Economics at MIT, while also taking up the Lemann Foundation Professorship in Economics at the University of Zurich. Her research has moved across health, education, financial inclusion, environment, and governance.
The experimental turn she helped lead has critics. Some argue that randomized trials answer narrow questions and cannot capture general equilibrium effects, political constraints, or the deep historical causes of poverty. Others worry about external validity: a result from one district may not travel. Ethical objections have been raised about withholding potentially useful services from control groups, though proponents note that resources are scarce and that untested programs can also waste them. Duflo’s response has generally been pragmatic rather than imperial. Experiments are a tool for learning about mechanisms and for discarding ineffective programs, not a substitute for theory, political judgment, or large-scale institutional reform. The influence of the approach is nonetheless hard to miss. Development economics shifted from mostly aggregate speculation toward a literature dense with field experiments, and finance ministries, aid agencies, and nonprofit organizations increasingly ask for evidence before scaling a program.
What distinguishes the body of work is less any single finding than a change in the standard of claim. Statements about the poor are expected to survive contact with carefully measured behavior. Incentives matter, but so do trust, convenience, and the daily friction of unreliable services. Education raises earnings, yet teaching has to meet students where they are. Credit is useful without being miraculous. Poverty, in this view, is not one trap but many small ones, some of which can be loosened by policies that are modest, testable, and therefore correctable. That stance—curious, empirical, and deliberately unromantic—is the center of Esther Duflo’s contribution to economics and to the practical fight against deprivation.