Larger Market

• The EU market is one of the largest markets in the world. Helped by the adoption by many of its members of the euro, a single European currency, the European common market creates various cross-border business opportunities for thousands of enterprises. For instance, German car makers can easily sell vehicles in France, French farmers can provide fresh produce to the UK, and the British can offer financial services to European businesses. Naturally, the more countries join the union, the better it is for business because firms need to comply only with the EU, rather than national, regulation and taxation systems, and can tap larger markets.
  
  

Cheaper Labor

• As it is primarily relatively poor countries that join the EU these days -- all the rich ones are already in -- their workers are content to labor for less money, lowering labor unit costs for businesses. For example, German and French manufacturers have moved much of their production to Eastern Europe, where wages are a fraction of those that the Western European workers demand. Producers then pass on these cheaper production costs to consumers in the form of lower prices.
  
  

Peace

• Because both world wars originated in Europe, a political union that involves France, Germany and many other former antagonists is welcome. Accordingly, peaceful relations between states that join the EU is another reason for EU enlargement. As of 2011, there was a debate inside the EU over whether Turkey should join the union; those in favor thought it would improve relations with the Muslim world.
  
  

Democratic Reforms

• The prospect of an EU membership often serves as a guiding spirit for the countries that want to join the European Union. For example, many Eastern European countries had to update their legislation to reflect common European values of democracy, human rights and the rule of law. Strong democratic institutions, such as independent media and courts, must also be established before a country can join the EU.