FEDERAL DEBT AND THE RISK OF A FISCAL CRISIS
"Over the past few years, U.S. government debt held by the public has grown rapidly—to the point that, compared with the total output of the economy, it is now higher than it has ever been except during the period around World War II. The recent increase in debt has been the result of three sets of factors: an imbalance between federal revenues and spending that predates the recession and the recent turmoil in financial markets, sharply lower revenues and elevated spending that derive directly from those economic conditions, and the costs of various federal policies implemented in response to the conditions.

Further increases in federal debt relative to the nation’s output (gross domestic product, or GDP) almost certainly lie ahead if current policies remain in place. The aging of the population and rising costs for health care will push federal spending, measured as a percentage of GDP, well above the levels experienced in recent decades. Unless policymakers restrain the growth of spending, increase revenues significantly as a share of GDP, or adopt some combination of those two approaches, growing budget deficits will cause debt to rise to unsupportable levels..."