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.
Breaking Down Ownership of US Debt. By mid-2015, the total amount of official debt owed by the federal, state and local governments was more than $18.5 trillion. That figure is expected to reach $21.6 trillion by the start of 2016.Some experts add more than $120 trillion in unfunded future liabilities on the federal government balance sheet.hy China Owns So Much US Debt. There are two main economic reasons why Chinese lenders bought up so many U.S. Treasuries. The first and most important is that China wants its own currency, the yuan, pegged to the dollar.