Research

Job Market Paper: "The Origins of the Nitrogen Revolution" (joint with Matteo Ruzzante)

Abstract: Many technologies raise productivity in locations constrained by their natural endowments yet diminish specialization across space. We show that the first commercial nitrogen fertilizers in history were one such “converging” technology. Leveraging natural variation in soil nitrogen deficiency and the sudden introduction of Peruvian guano and nitrates to 19th-century England, we provide two main empirical findings. First, locations specialized on the basis of their natural endowments before the introduction of fertilizer: nitrogen-deficient places devoted less land to nitrogen-intensive crops. Second, combining newly-digitized data and a difference-in-differences design, we show that these nitrogen-deficient places substantially reallocated toward nitrogen-intensive crops after fertilizer was introduced, indicating convergence across space. To quantify the welfare impact of this “converging” technology, we embed fertilizer into a quantitative spatial model of the English agricultural sector with realistic geography. The welfare gains from fertilizer were equivalent to two decades of annual productivity growth in agriculture. However, convergence implies a reduction in the gains from trade, which offsets up to 10% of these welfare gains under plausible trade cost regimes.

Other Research Papers

"Integrating a Nation: Evidence from Railroads and Telegraphs"

Abstract: Increases in market integration are widely viewed as crucial for economic growth. Yet, there is conflicting evidence about the role of technological progress in transportation and communication technology in bringing about greater market integration. We make progress by leveraging high-frequency grain price data with the staggered timing of the construction of railways and telegraphs in mid-19th century Britain. We document that the connection of a city pair to the railway networks led to a sizable increase in the probability that they had cointegrated grain prices, which rose over time and is consistent across sample restrictions. The positive increase from railroads was heterogeneous depending on the year of connection, however: towns connected during the era of the “railway mania”, which featured significant overinvestment in the network, saw null effects on market integration. By contrast, we find that the telegraph only increased market integration between distant cities, with no effect on nearby cities and null effects overall. These results suggest that these technologies both contributed to improved market integration, but not uniformly in all circumstances.

Competition and Innovation in the Industrial Revolution: Evidence from France (joint with Lukas Rosenberger and Zincy Wei, draft available upon request)

We examine how competition influenced innovation during the first Industrial Revolution using data from 19th-century French national industry expositions. We link exhibitors across expositions and to French patent records, allowing us to track entry, exit, and innovation patterns at the individual inventor level. Initial findings suggest that while new entrants frequently exhibited high-quality inventions, returning exhibitors rarely upgrade their quality. Top performers often received ``reminder awards'' for previously exhibited products, indicating reduced incentives for re-innovation. We exploit a shock generated by the sudden and unexpected exit of around one quarter of exhibitors following the Napoleonic Wars to provide causal evidence on these mechanisms.

Work in Progress

The Diffusion of New Commodities: Evidence from the Danish Sound Dues

Taxing Energy? The Role of Coal Duties in the Spatial Economy of Industrializing Britain