Conference Agenda

I study a nationwide gas stove program which aims to convert Peruvian households from wood-fuel cooking to liquefied petroleum gas (LPG) cooking. Using 16 waves of Peru’s Demographic and Health Survey, I show that infant mortality increases by 15% on average as a result of the intervention. Subsidizing LPG also causes a higher incidence of symptoms of acute respiratory infections in under-5 children and of moderate or severe anemia among adult women. I provide suggestive evidence that these health impacts are due to an increase in total exposure to air pollutants and to unanticipated behavioral effects of the intervention.

Ever more countries consider reducing the cost of public transport to incentivize shifts to more sustainable transport modes. This paper quantifies the welfare effects of a large-scale, nationwide public transport subsidy in Germany–the so-called Deutschlandticket. We pair novel cellphone- and app-based mobility data from several European countries with recent advances in synthetic control methods to examine the impacts on mobility and external costs. Our findings show a persistent increase in train ridership and a substitution away from car travel (number of trips, kilometers driven, and vehicle counts). We find no evidence for latent demand as total mobility remains constant. The substitution is the largest in cities with high-quality public transport as well as for trips of longer distances. The implied CO2 emissions reduction amounts to around 5.3 million tons per year (3.7% of total road transport sector emissions). In line with our results on less road traffic, we also find strong evidence for reduced air pollution in cities (NO2 concentration) and lower road congestion (travel time per kilometer). A cost-benefit analysis reveals that the overall benefits of the policy outweigh its associated costs (benefit-cost ratio of 2.1). Similarly, the marginal value of public funds amounts to 1.3, implying that the program costs just €1 for every €1.3 that it provides in benefits.

Poor air quality causes substantial health issues and cognitive harm, particularly to the young. We conducted an RCT providing air purifiers to grade-2 classrooms in Lahore, Pakistan. The intervention initially reduced indoor PM2.5 concentrations by 25\%, from a base of 191 $\mu g/m^3$; and caused large gains in test scores (0.15 SD) three weeks after installation, accompanied by improvements in classroom behavior. Gains are concentrated in math and fluid intelligence, with no improvement in English or crystallized intelligence. However, six weeks later, the treatment becomes ineffective, ceasing to improve air quality and resulting in no detectable gains in test scores.

Ecosystem restoration is increasingly promoted as a global strategy to combat biodiversity loss, climate change, and environmental degradation. Yet robust empirical evidence for long-term, cost-effective recovery at national scales remains limited. Critics also emphasize that restoration outcomes are often context-dependent and that trade-offs and costs are poorly quantified. Here we show that China’s ecological reforestation programs (ERPs) generated substantial ecological and public health benefits including climate extremes mitigation, air and water quality improvements, and biodiversity recovery, all without compromising agricultural productivity. Over two decades, monetized health gains from the ERPs exceeded program costs ten times over. Using China as an empirical benchmark, we construct a global return-on-investment map for forest restoration. This projection identifies regions where reforestation could yield comparably high returns.