Center for International Development Working Paper Series November 2006 HKS Authors See citation below for complete author information. Ricardo Hausmann Rafik Hariri Professor of the Practice of International Political Economy Federico Sturzenegger Adjunct Professor of Public Policy Citation Hausmann, Ricardo, and Federico Sturzenegger. "The Implications of Dark Matter for Assessing the U.S. External Imbalance." Center for International Development Working Paper Series (CID-137), November 2006.