⁴The number of papers applying the cointegration methodology has recently risen considerably. References include Bertaut (2002), Byrne and Davis (2003), Fernandez-Corugedo, Price, and Blake (2003), Pichette and Tremblay (2003), Catte, Girouard, Price, and Andre (2004), Lettau and Ludvigson (2004), Hamburg, Hoffmann, and Keller (2005).