There is also a concern that there is a lack of demand of oil. And so when commodity prices fall, it's good if you happen to be a consumer, but it's sometimes seen as symptom of a weakening economy.

I think the Chinese are really amateurs when it comes to running markets.

China's stock market is not very big. And yet when stock market has a bad day in China, it seems, Europe has a bad day and then we have a bad day.

If you don't have a set of principles that you can explain for what you are doing, then how can anybody know what you're going to do next?

I think it's hard to understand in economics. It's easier to understand on psychology.It's a kind of panic or a sense that the world economy is just not in as good shape as we thought and so everybody is chasing everybody else.

I think what the Fed fears is that, if Donald Trump gets big tax cuts and big spending increases that take effect right now, when the economy is close to full employment, they will have to raise rates more rapidly.

I think it was seen as a symptom that the Chinese leadership may be really scared about their economy.Why would you want to depend more on exports if you're a country that has a stated policy of relying less on exports and more on consumer spending, domestic spending?