Fujiki (2003, 2006) extends the Freeman (1996) model to a two-country model, and demonstrates that elastic money supplies in foreign exchange markets yield efficiency gains in monetary equilibrium, and that several institutional designs achieve the desired elastic money supplies equally. This paper considers four institutional designs using a simplified version of the model of Fujiki (2003, 2006), which includes a central bank intervention in foreign exchange markets, a combination of central bank discount window policy and the CLS Bank, foreign currency supply operations based on central bank swap lines, and cross-border collateral arrangements. These institutional designs yield the same efficiency gains in our model.