This article's point of departure is the observation that global modelers characteristically do not justify their policy recommendations in terms of social optimality criteria. Instead, they simply compare the forecasts of their descriptive models with the simulations of their prescriptive models. This article attempts to clarify why social optimality criteria are necessary in global modeling and how such criteria can be constructed. In this vein, the socially optimal paths of policy targets are derived for a simple, illustrative global model.