In response to a request by Senator Tom Harkin, the Food and Agricultural Policy Research Institute (FAPRI) has evaluated a number of issues related to the lock and dam system on the Upper Mississippi and Illinois Rivers. One critical issue is how future demand for agricultural exports will affect the demand for river transportation services. This paper sketches a theoretical framework for economic decision-making regarding the upgrade of the lock and dam system of the Upper Mississippi River and then compares export projections underlying analyses by the U.S. Army Corps of Engineers (USACE) with recent projections by FAPRI and the International Food Policy Research Institute (IFPRI).