Agriculture is a set of biological processes that are guided by human intervention. Thus, understanding agricultural systems requires consideration of both the biology of production and the economic factors that drive human decisions. For example, crop production may be affected by abiotic factors (e.g., nitrogen use or irrigation) or biotic factors (e.g., pests and diseases). However, farmers manage their crops, for example by choosing when, where and how much fertilizer and pesticide to apply, and whether to plant disease-resistant varieties. These choices are driven by economic factors, such as the prices of inputs and outputs and the farmer’s preference for risk. InSTePP takes an interdisciplinary approach when appropriate, combining the insights from agricultural and other biological sciences within frameworks that are solidly supported by economic theory.