Description:

Speaker: Christopher Sims

Title: The Origins of the Nitrogen Revolution (joint with Matteo Ruzzante)

Abstract: Natural soil endowments have historically constrained agricultural productivity and population growth. The 19th century witnessed technological breakthroughs, such as nitrogenous fertilizers, which alleviated these constraints and paved the way to more intensive farming. In this paper, we examine the introduction and rapid diffusion of guano in 19th century England. We first establish that nitrogen deficiency shaped cropping patterns prior to guano’s arrival. Drawing on newly digitized agricultural census data and leveraging the discovery of Peruvian guano as a natural experiment, we show that nitrogen-poor areas reallocated their production toward nitrogen-demanding, more profitable crops. These same areas also experienced increases in livestock counts, consistent with a shift to “high farming” practices. The effects are driven by (i) areas with heavy soils, where fertilizers complemented a contemporary innovation in drainage, and (ii) regions with initially lower agricultural productivity. Our results are corroborated with analysis using detailed price and sales data covering a panel of English towns over the same period. We conclude by discussing preliminary work on the welfare implications of this shock.