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.
The Urban Institute. Debt is distributed quite unevenly across the United States, as the map above from the Urban Institute shows. In 2013, average total debt ranged from a high of nearly $100,000 in San Jose, California, the heart of Silicon Valley ($97,150), to less than $25,000 in McAllen, Texas. The report notes that the top 20 percent of tracts account for 42 percent of all debt holdings in America.