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.
As of December 15, 2015, the U.S. is $18.8 trillion in debt. There are two basic categories of debt owners: 1) the public, which includes foreign investors and domestic investors and, 2) federal accounts, also known as intragovernmental holdings.. Each category is explained below.