Conference Agenda

Ecosystem services are essential to economic activity, yet their social value is difficult to quantify since markets rarely internalize the externalities they generate. This paper provides causal evidence on the economic value of ecosystem services by studying bees, the primary pollinators in modern agriculture. Assembling comprehensive data on U.S. agriculture and bee colonies, we construct a county-by-year measure of local bee services that combines variation in regional bee supply, crop-specific pollination demand, and local crop structure, and link it to revealed local economic outcomes. To address endogeneity, we develop a novel instrumental-variables strategy that exploits the seasonal migratory behavior of commercial bees, using machine-learning methods subject to ecological constraints to trace exogenous colony shocks across space. Our IV estimates indicate that the economic value of an additional colony is approximately $5,271—an order of magnitude larger than the observed rental price. The implied aggregate value of U.S. bee colonies exceeds $14 billion annually, highlighting large unpriced benefits in ecosystem service provision and the potential gains from conservation and coordination policies.

While the economic and social benefits of foreign aid and development finance receipt are well-established, relatively little is known about the environmental impacts in recipient countries. China has undertaken overseas investment projects on a massive scale across more than 140 countries. This paper quantifies their impacts on key ecological outcomes: deforestation, land use, air pollution, and biodiversity. Using 6,303 geocoded Chinese finance projects from 2000-2023 combined with satellite and biodiversity data, we find that project implementation leads to an immediate and persistent decline in surrounding vegetation by 0.3%, equivalent to an average annual loss of 4,755 km2 of vegetated land worldwide. Air quality also deteriorates, with aerosol optical depth rising 0.9%. Biodiversity losses are concentrated among higher trophic groups: bird species richness declines by 1.6% and mammalian richness by 0.1%. Translating vegetation loss into reduced carbon sink capacity implies annual emissions of 52-174 million tons of CO2e, corresponding to annual global welfare losses of $2.6-$33.1 billion.

We estimate the economic value of biodiversity by estimating the value of pest control services provided by migratory birds to U.S. agriculture and forestry. Exploiting exogenous variation in migratory bird returns driven by winter habitat conditions in South America, we find that a 10% decline in avian biodiversity reduces crop revenues by 1.1% and increases forest pest outbreaks by up to 1.2%. We find that the elasticity of substitution among bird species is high in agricultural landscapes and lower in forests, implying that ecosystem service provision in agriculture depends more on the total abundance of birds, while in forests it depends more on the number of species. These findings identify biodiversity as a productive input and highlight cross-border externalities from environmental degradation.

Biodiversity has reemerged as a central focus in research on ecosystem–economy interactions, and a canonical challenge is to disentangle the value of species variety from that of sheer abundance of individual organisms. This paper provides the first causal evidence that real estate markets value species diversity of street trees in a mega-urban setting. We study New York City’s street-tree changes from 1995–2015, a period marked by substantial shifts in species composition. Our identification strategy exploits the Asian longhorned beetle outbreak, an invasive pest that prompted the targeted removal of susceptible host species and their replacement with non-host species. This response generated quasi-experimental variation in species richness while leaving total tree abundance largely unchanged. Over the two decades of the study period, our estimates suggest that approximately 7.4% of housing price growth can be causally attributed to changes in street tree species richness. We further show that increases in functional diversity associated with enhanced aesthetic and experiential attributes, such as year-round foliage presence, variation in flowering patterns, and root-system diversity that may improve stormwater absorption, are strongly correlated with the housing market capitalization of species diversity.

The processing of animal hides and furs releases carcinogenic pollutants that pose global health risks. Yet, there is a lack of direct evidence linking this trade to human health outcomes. Here we show that China’s 2008 ban on processing trade for animal hides and furs led to marked declines in local tumor incidence (86.35 cases per 100,000 individuals) and tumor mortality (49.45 cases per 100,000 individuals). The reductions are particularly evident for lung, liver, and stomach cancers, largely driven by decreased exposure to hexavalent chromium [Cr(VI)], a toxic by-product of tanning. After the ban, production shifted to other regions (some EU and Southeast Asian countries), which shows the transboundary nature of industrial health hazards. These findings reveal that global trade policies can yield substantial public health consequences and underscore the need for coordinated measures to reduce carcinogenic emissions from the hides and furs industry.