To what extent were the U.S. budget deficits of the 1980s and 2000s caused by higher spending versus lower tax revenues? Using the Economic Report of the President, explain which categories of spending or taxes were most responsible. As a share of GDP, what was the balance for the primary budget in 1985, 1999, 2006, 2010, and in the most recent available year? How does this compare with the total budget balance?