Euro zone integrates faster with US than internally, ECB's Vujcic said

Vujcic said estimated barriers to cross-border equity investment between the euro zone and the United States have fallen by a quarter since 2014, more than twice as much as barriers within the euro area. "Strikingly, we are integrating faster with the United States than with each other," he said.

He also pointed to evidence that Europe's fragmented capital markets make the economy less resilient. ECB research shows that firms with mainly domestic shareholders cut investment about 20% more than peers with international investor bases during the COVID-19 shock, he said. European companies also tend to scale back investment when oil prices rise, unlike US firms.

"In a fragmented Europe, investment becomes the margin of adjustment whenever a shock hits," Vujcic said. "That is a resilience problem before it is a growth problem."