A single currency bloc requires flexible labour, competitive product markets and a fiscal policy that can effectively offset the pain from a business downturn affecting one region.
Seven years after the euros launch, many of these elements are largely missing in the euro area.
Moreover the deeper political integration that monetary union was expected to foster in order to help push through these reforms has not occurred, the study released by Centre for Economic Policy Research said.
Despite the highly successful launch of EMU, it remains an open question whether national economies will prove to be sufficiently flexible to enable smooth adjustment in the event of a major asymmetric shock or a financial crisis, said the studys author Philip Lane, economics professor at Trinity College in Dublin.
The European Union had agreed to aggressive economic reforms in the Lisbon Agenda to accompany monetary union. But the programme has foundered and its objectives have been watered down.
European Union leaders are holding a two-day summit in Brussels on how to promote jobs in a region where unemployment is stuck over 8 percent and economic growth scarcely reaches 2 percent.
Politicians sometimes blame the European Central Banks monetary policy for the slow growth they face.
But the CEPR report, called The Real Effects of EMU and published this month, points to weaknesses in the economic structures of the region, not to ECB policy.
Trade and financial integration is cited as a clear economic benefit from a single currency. Trade as a ratio of GDP has grown in every EMU country. In Austria it has risen from 52.6 in 1995 to 82.1 in 2004, Lane calculated.
However, international trade is up worldwide and intra-regional trade has not grown as dramatically.
Financing costs for business and government are also down, which in turn bring economic benefits. Corporate debt issuance has risen to 74.5 percent of GDP from 32.2 percent of GDP before monetary union, it added. The debit side of the ledger, though, is somewhat longer.