The purpose of this study is to show the importance of the geography of demand in ecological economics and to provide guidance for future research efforts to incorporate it. The analysis examines gaps in the literature that deal with the spatial variability of potential beneficiaries to ecosystem services and demonstrates the quantitative importance of defining the geography of demand. Since ecosystem service value is anthropocentric, incorporating those who receive benefits into the economic accounting method is a necessary requirement. As the total benefits received from ecosystem functioning declines over space, so too does its economic value. There are two study areas in Illinois used in the analysis. The first is the Des Plaines River wetlands in the Chicago metropolitan area and the other is the Cache River wetlands in rural southern Illinois. This study finds large ranges of value for ecosystem services when the decay of value over space is incorporated. Also, these findings suggest a minimum spatial requirement depending on the scale of aggregation. For a county level scale, a minimum economic jurisdiction of 1,000 km is suggested. Finally, the presence of large numbers of beneficiaries near an ecosystem has the greatest influence on value when the economic jurisdiction is spatially limited. From the steepest distance decay function to the shallowest the Des Plaines wetlands returned a range of values from approximately $971,000 to $2.3 billion and the Cache wetlands values ranged from $0 to $2.5 billion. This paper is not intended to be a case study for the economic valuation of a specific area but rather a demonstration of the necessity for a spatial economic framework that accounts for the delivery and receipt of ecosystem services over space.