Four of the 15 EU nations are not joining the single-currency club. But the British population has been skeptical about the continent's single currency, and Britain will not join until voters approve in a referendum. Sweden and Denmark are staying out for similar reasons of skepticism. Norway and Switzerland are not EU members and thus not eligible to join, and neither wants to. Europe's newest democracies, such as Poland, Hungary and the Czech Republic, will be outside Euroland even as their economies continue to integrate more fully with Western Europe.
Critics contend real economic unity is impossible without political unification.
Euroland's 11 economies vary enormously in size and strength, and are growing at various rates. Throughout the past year of global economic upheaval, the European economy has shown remarkable resiliency, which has helped smooth the run-up to the euro's launch. But some doubt whether the 11 Euroland countries will be able to hold together in the face of financial-market or currency turmoil, or a severe recession, that strikes closer to home. Despite these potential problems down the road, monetary unification already has achieved a remarkable convergence among the 11. In the space of a few years, they lowered inflation and budget deficits, in some cases dramatically.