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.

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.

There is the fact that - people have had a lot of confidence that the Chinese leadership could fix what is wrong with their economy so it wouldn't have ripple effects around the world. I think that confidence is being shaken by how difficult it is for them to manage their stock market and their currency.

It may be that the U.S. stock market starts to rise if people think it's gone far enough.

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 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?

At some point, people may decide that the U.S. stock market has fallen enough. After all, the U.S. economy seems to be getting better, that what happens in China is not going to have that devastating effect on car sales here or how many people buy Apple phones or what happens at - how many people shop at Wal-Mart.