On economic and social issues, EU member states have given up their national sovereignty because the EU decision-making has been transferred into the hands of a supranational authority.
The European Union started with six Western European countries after World War II as the European Coal and Steel Community in 1952 (Belgium, France, Italy, Germany, Luxembourg, and the Netherlands). By 1973 the United Kingdom, Denmark, and Ireland joined what had become known as the European Community. Greece became a member in 1981, Spain and Portugal in 1986, Austria, Finland, and Sweden in 1995, eight former communist countries in 2004 (the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia, and Slovenia) plus Malta and Cyprus, Bulgaria and Romania in 2007, and Croatia in 2013, the 28th member.
A recent primer on the EU attempts to clarify the dysfunctional union of 28 countries which has not been very successful in promoting “peace, stability, and economic prosperity,” by harmonizing laws and common policies on economic, social, and political issues as envisioned by a hand full of European socialist elitists.