5  Empirical studies show that the links between countries are particularly tight when countries simultaneously sustain the same shock. See, for example, J. Boivin and M. Giannoni, “Global Forces and Monetary Policy Effectiveness,” in International Dimensions of Monetary Policy, J. Gali and M. Gertler (eds.) (Chicago: University of Chicago Press, 2008).
6  Recent research at the Bank of Canada has empirically demonstrated that the financial channel plays a key role in the transmission of shocks originating from the United States. See K. Beaton and B. Desroches, “Financial Spillovers Across Countries: The Case of Canada and the United States,” Bank of Canada Discussion Paper No.