A number of authors have used the concept of an optimum currency area (or OCA) index to assess the relative proximity of various pairs of economies to the ideal of an optimum currency area. Alas, a significant deficiency of this approach as used so far is that it provides no room for long-term real income convergence - a frequently observed process that can be viewed as a specific type of long-term asymmetric shock. In this paper, a novel way to construct the OCA index is suggested that is sensitive to any real convergence (or divergence) between the two economies under study. Estimation of this convergence-sensitive OCA index for a sample of OECD economies yields an intuitively plausible result: real convergence gains on significance within the OCA index after an initial sample, a group of advanced OECD economies, is broadened with a group of emerging economies. Applied to the 2001-2008 period, the convergence-sensitive index shows a few Central and Eastern European late-transition economies to be better prepared for a common currency with Germany than several current euro area members.
optimum currency area OCA index real convergence real exchange rate trend appreciation