Abstract: The speed at which structural change from agriculture to non-agriculture takes place is a key determinant of successful aggregate growth in developing countries. We show that crop-level differences in agricultural technology – the coefficients on factor inputs in the production function – account for a substantial portion of cross-country differences in agricultural labor productivity, agricultural labor share, and per capita income. Using a sample of 100 countries we document technology differences across major crop types and illustrate their quantitative implications for structural change and development. Counterfactually eliminating technology heterogeneity in our sample results in 25\% lower variance in log income per capita, and 60\% higher median per capita income.