The Euro: How a Shared Currency Shapes 340 Million People
The Creation
The euro was launched on January 1, 1999, as an accounting currency, with physical notes and coins entering circulation three years later. It was the culmination of a decades-long project to bind European economies together closely enough that another war between France and Germany would be unthinkable. The Maastricht Treaty of 1992 set the convergence criteria: countries had to demonstrate low inflation, sustainable public finances, stable exchange rates, and low long-term interest rates to join.
Nineteen of the 27 EU member states use the euro, covering about 340 million people. The most notable holdouts are Denmark, which negotiated a formal opt-out, and Sweden, which technically meets the criteria but has chosen not to join. Poland, Czechia, Hungary, and other newer member states are legally obligated to eventually adopt the euro but have not set dates.
The Trade-Off
Sharing a currency means sharing monetary policy. The European Central Bank sets interest rates for the entire eurozone based on aggregate economic conditions. The problem is that the eurozone is not a single economy. When Germany is growing rapidly and needs higher interest rates to cool inflation, Greece might be in a recession and need lower rates to stimulate growth. One interest rate cannot be right for every country simultaneously, and national governments cannot use currency depreciation to regain competitiveness.
This is the fundamental tension of the euro: monetary union without political union. In the United States, when a state like Mississippi experiences an economic shock, federal fiscal transfers — Social Security, unemployment benefits, infrastructure spending — automatically cushion the blow. The eurozone has no comparable fiscal mechanism. Its central budget is roughly 1 percent of EU GDP, compared to the U.S. federal budget of about 20 percent of GDP. This gap was brutally exposed during the sovereign debt crisis of 2010-2015.
The Global Role
Despite its internal tensions, the euro is a global success. It is the second most traded currency after the dollar, the second most held reserve currency, and the currency in which about 20 percent of global foreign exchange reserves are held. The euro has given European companies the ability to price contracts and borrow money across borders without currency risk. A German exporter selling to a Spanish buyer invoices in the same currency it pays its workers.
The euro's stability during the pandemic — when EU member states agreed to joint borrowing for the first time through the NextGenerationEU recovery fund — demonstrated that the currency union can evolve toward greater fiscal integration when the political will exists. Whether that momentum continues depends on whether European voters and governments see the benefits of deeper integration as worth the loss of national fiscal sovereignty.
The Edge Review explains economics for general readers. The European Central Bank publishes detailed data on euro area economic conditions.