OCA with stationary expectations

Published by Mundell in 1961, this is the most cited by economists. Here asymmetric shocks are considered to undermine the real economy, so if they are too important and cannot be controlled, a regime with floating rates is considered better, because the global monetary policy (interest rates) will not be fine tuned for the particular situation of each constituent region.The four principal criteria for a successful currency union are:Labor mobility across the region. This includes physical ability to travel (visas, workers' rights, etc.), lack of cultural barriers to free movement (such as different languages) and institutional arrangements (such as the ability to have superannuation transferred throughout the region) (Robert A. Mundell). In the case of the Eurozone, while capital is quite mobile, labour mobility is relatively low, especially when compared to the U.S. and Japan.Product diversification: The Eurozone scores quite well on this criterion, and monetary integration seems to further improve the diversification of production structures.Openness with capital mobility and price and wage flexibility across the region. This is so that the market forces of supply and demand automatically distribute money and goods to where they are needed. In practice this does not work perfectly as there is no true wage flexibility. (Ronald McKinnon). The Eurozone members trade heavily with each other (intra-European trade is greater than international trade), and most recent empirical analyses of the 'euro effect' suggest that the single currency has increased trade by 5 to 15 percent in the euro-zone when compared to trade between non-euro countries.