The medium-sized economies of Europe are better served by the foreign exchange market put in place by the single currency of the euro, it has been claimed.Writing for the Telegraph, Jeremy Warner suggests that countries such as Germany and France - described as the "core union" of the continent - might perform better economically if their fortunes were detached from their smaller neighbours.Similarly, he adds, the smaller economies in the European foreign exchange market could find themselves better able to respond to financial pressures if they were subject to lower exchange rates.However, Mr Warner argues that the euro has proved successful since its introduction into the world currency market and throughout the recent economic turbulence."The crisis has enhanced the euro's appeal as a reserve currency alternative to the dollar," he writes.For the continent's tourism markets, the recent strength of the euro in the foreign exchange market could be driving visitors further east.Bob Atkinson, travel expert at travelsupermarket.com, recently suggested that Hungary, Bulgaria and Poland are all relatively cheap compared to nations within the eurozone.