This document discusses Special Drawing Rights (SDR) and Optimum Currency Areas (OCA). It defines SDR as an international reserve asset created by the IMF in 1969 used for balance of payments settlements. It explains that SDR was created to support the Bretton Woods system and is now valued as a basket of currencies. The document also outlines OCA theory and criteria for an optimal currency region, noting regions with openness, diverse production, mobile labor and homogeneous preferences are more suited for a single currency. It concludes benefits of an OCA include reduced costs and increased trade while costs include constrained monetary and fiscal policies.