One of the fathers of modern finance and a winner of this year’s Nobel prize for economics said the bloated deficits of the United States and European nations may lead to a worldwide recession.

Eugene Fama, whoe “shared the economics prize for research into market prices and asset bubbles” with Robert Shiller and Lars Peter Hansen, told Reuters on Saturday that the markets may not find the debts of European nations and the United States to be credible.

Fama, who is a professor at the University of Chicago, also played down the United States’s stronger labor market data from last month.