Why Was the Wheel (Not) Used in the Andes? A Hypothesis Explaining the Slow Adoption of Wagon Transport and Evidence from Nineteenth-Century Colombia

The slow adoption of wagon transport in the Andes is a puzzle. We examine it by developing a threshold technology-adoption model calibrated using human and mule energy consumption and unique historical data from a human trail and the first wagon road in the Andes. Model predictions align with historical social choices. Pre-Columbians selected a straight, steep, short route for human porters to reduce energy costs, while the Spanish used it with mule packs. Late nineteenth-century transport demand growth surpassed the model’s threshold and contributed to construction of the zigzagging, gentle, long wagon road route, as well as incentives to build state capacity.