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.
Everybody knows that the US is the worldâs biggest borrower, owing a massive amount of money to China, which holds $1.15 trillion in bonds issued by Uncle Sam. With more than $16.2 trillion in debt â including the money the US owes to itself to pay for programs like Social Security â the US debt-to-GDP ratio is around 100%. (Not counting so-called intragovernmental holdings of debt, the ratio is more like 68%, according to the Government Accountability Office.)