Working Papers 

-Water Reservoirs as Drought Adaptation: Economic and Demographic Impacts in Northeast Brazil. (with B. Jeddi and D. Keiser). 

Can societies adapt to more frequent and intense weather disasters? We estimate the value and the limit of disaster adaptation in Northeast Brazil, a semi-arid region with a long history of droughts. The main contribution of this paper is the identification of the effects of drought frequency and reservoir construction on economic and population outcomes.  We create a dataset that replicates the network of rivers and monitoring stations in Brazil and we use within state-biome variation in extreme river flow and river gradient to identify the impact of drought frequency and the adaptation value of reservoir placements. We find that the adaptation value of reservoirs is large but declines rapidly with drought frequency. Adding a reservoir offsets the impact of an increase in drought frequency on GDP per square kilometer by 27\% and on population density by 26\%. However, the contribution of a reservoir declines to zero at a frequency of 3 droughts per decade. Reservoirs expand subsistence agriculture, increasing vulnerability, but also accelerate rural-urban migration, improving resilience.

-Roads, Trade, and Development: Evidence from the Agricultural Boom in Brazil. (with He, X., and W. Zhang).

This study examines how trade liberalization affects the impact of road infrastructure on economic development in Brazil. Using a triple-differences framework and instrumental variables, it finds that road expansion post-trade reform increases population and GDP per capita in high soybean potential areas. Additionally, road expansion boosts soybean harvested area and yield in these regions, highlighting the role of export-led agricultural growth in economic development. 

-Technology Adoption and the Agricultural Supply Response Function

This study examines the impact of technology diffusion, specifically genetically modified and nitrogen-fixing soy, on agricultural supply in Brazil. Using data from 1.5 million farms, it estimates price effects on soy acreage expansion from the 1996 and 2006 agricultural censuses. Findings show that acreage response functions are more elastic near the agricultural frontier due to technological diffusion. The adoption of nitrogen-fixing soy, which converts marginal savanna pastureland to soy production, largely explains this heterogeneity. The long-run price elasticity of soy acreage is 0.6 in the south and 1.8 in the savanna. Near the savanna-Amazon border, a 10% permanent increase in soy prices could convert 1 million hectares of natural vegetation to farmland. 

-Relational Contracts and Innovation: Evidence from the Double-cropping Boom in Brazil

Technological advances in the 1970s and 1980s enabled soybean cultivation in the Brazilian Savanna, but regional constraints limited adoption. Post-macroeconomic reforms, international traders introduced contracts bundling technology, finance, inputs, and market access. Analysis of farm-level data shows these contracts led to rapid technological diffusion, agricultural expansion, and a 10-fold increase in productivity by converting marginal land to soybean plantations.