Will Greece exit the eurozone? Hard to believe, but the answer to this question could determine the fate of the U.S. economy this year. Global investors have been driving stock prices down, as odds rise that Greece will quit the European currency union.

If the eurozone fractures, the U.S. economy will have a big problem. The fragile stock market will fall sharply and it will become much more difficult for U.S. firms to borrow.

Read more in the Philadelphia Inquirer.