"Europe, the source of the Enlightenment, the birthplace of modern science, is in crisis.” So says Joseph Stiglitz, Nobel Prize-winning economist and sometime chairman of President Bill Clinton’s Council of Economic Advisors.

“Large parts of Europe” have endured “a lost decade”; incomes per head are “lower than before the [2008] global financial crisis”. While Germany is doing “relatively well”, there’s “soaring youth unemployment” in France, Italy and Spain. “In a well-functioning economy, there’s rapid growth, the benefits of which are shared widely,” Stiglitz writes, but “in Europe we see the opposite”.

So what, he asks, is the “big policy problem”, Europe’s “one underlying mistake”? To some, his conclusion may be surprising. For Stiglitz points his finger squarely at “the fatal decision to adopt a single currency, without first providing the institutions to make it work”.