Joseph Stiglitz, a Nobel-Prize winning economist, says cryptocurrencies should be shut down. He worries that they enable illicit activity by making money transactions less transparent.
Still, he sees the value in digital payments systems and supports electronic use of government-backed currencies like the dollar.
"I've been a great advocate of moving to an electronic payments mechanism. There are a lot of efficiencies. I think we can actually have a better regulated economy if we had all the data in real time, knowing what people are spending," he says.
Watch the video above for more from Joseph Stiglitz on digital payments and cryptocurrencies.