Defaulting on the nation's debt would be cataclysmic. The U.S. Treasury's Aaa rating is the one constant in the world's financial system. When times are bad anywhere on the planet, global investors flock to Treasury bonds because they know they will get their money back.

Our biggest challenge is to eliminate the popular perception that economists don't have anything useful to say.

We need to get rid of the debt ceiling law. It's anachronistic and it's a problem.

Housing was ground zero for the Great Recession. Between early 2006 and Obama's inauguration in 2009, average house prices fell by a third across the country. In certain areas, including cities as diverse as Akron, Orlando and Las Vegas, house prices fell by more than half.

Potential home buyers have a two-step decision process. First, they determine whether they can afford to make a purchase - does their income safely cover their mortgage payment? Then they determine whether owning is a better financial choice than renting - are the costs of owning a home lower than the cost of renting it?

It is hard to be enthusiastic about the economy's prospects when house prices are falling: Households spend less, small business owners can't use homes as collateral for loans and local governments are forced to cut jobs and programs as property-tax revenue disappears.

The principal linkages between Japan and the U.S. global economies are trade, financial markets, and commodity markets.