Europe's Single Market

The European Union's single market is the deepest example of economic integration among sovereign states. The 1957 Treaty of Rome created the European Economic Community, whose customs union was completed in 1968 with no internal tariffs and a common external tariff. But many barriers remained, such as differing product standards and border checks.

The 1979 Cassis de Dijon ruling by the European Court of Justice established that goods lawfully sold in one member state should generally be accepted in others, and the Single European Act of 1986 set a target of completing the market by the end of 1992. The result was the 'four freedoms': free movement of goods, services, capital and people.

Supporters credit it with boosting trade, competition and consumer choice; critics argue it limits national control over regulation and immigration. Britain's decision to leave the EU, completed in 2020, and its exit from the single market at the start of 2021 showed how hard unwinding such integration can be.