A Nobel Prize-winning economist says Trump should tread carefully with his trade policy

Business Insider senior editor Josh Barro sits down with Paul Krugman, a Nobel Prize-winning economist and distinguished professor of economics at the City University of New York. Barro asks Krugman for his thoughts on Trump's threats with regards to global trade, including a withdrawal from NAFTA.

Krugman says something like that would be a huge issue, and points out that there's no such thing as American manufacturing - that it's more accurately described as North American manufacturing, considering how interconnected the US has become with Mexico and Canada. He says disrupting NAFTA would be very costly, and says that trade will be the way we can tell whether there's any Trump unorthodoxy left. From a labor perspective, Krugman says that immigrant workers aren't competing with US-born ones anymore, but rather other immigrants.