The permanent income hypothesis implies that frictionless open economies with exhaustible
natural resources should save abroad most of their resource windfalls and, therefore, feature current
account surpluses. Resource rich developing countries (RRDCs), on the other hand, face substantial
development needs and tight external borrowing constraints. By relaxing these constraints and
providing a key Þnancing source for public investment, resource windfalls might then be associated
with current account deÞcits or at least low surpluses. In this paper, we develop a neoclassical model
with private and public investment and several pervasive features in RRDCs, including absorptive
capacity constraints, ine!ciencies in investment, borrowing constraints, and capital scarcity. We
use the model to study the role of investment and these frictions in shaping the current account
dynamics under windfalls. Since consumption and investment decisions are optimal, the model also
serves to analyze current account norms (benchmarks). We apply the model to the Economic and
Monetary Community of Central Africa and discuss how our results can be used to inform external
sustainability analyses in RRDCs.