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.
Updated August 15, 2017. The U.S. debt is $19.8 trillion. Most headlines focus on how much the United States owes China, one of the largest foreign owners. What many people donât know is that the Social Security Trust Fund, aka your retirement money, owns most of the national debt.