Note: As Mike Yassa, the lead author on the study, pointed out to me, the study did not actually test whether consuming caffeine before a task enhances memory, the problem being that other confounding factors can then lead to difference in performances on the test.
The US debt is more than $20.1 trillion, the largest in the world. Here are the 3 reasons it grew so large, and how it damages U.S. economic growth. The US debt is more than $20.1 trillion, the largest in the world.
Jess Jiang/NPR. China holds about $1.2 trillion in U.S. government debt, according to the Treasury Department's latest figures. That's about 30 percent higher than the previous estimate.This is part of those global imbalances we keep talking about. China exports more than it imports; the U.S. imports more than it exports.or China, the U.S. is too big to fail. And it's not just China. Japan holds nearly $900 billion in U.S. government debt. In all, U.S. debt held abroad totals some $4.4 trillion. 1  Share. 2  Facebook. 3  Twitter. 4  Google+.