from the Committee For A Responsible Federal Budget Project:
This situation is economically impossible; at some point, U.S. debt would reach a level so high that creditors would stop lending us money. The question, though, is how the situation will be resolved. Will politicians confront the policy choices or delay them to the point where they will be forced upon us due to a fiscal crisis? The longer we wait to take on these issues, the worse they will get and the more painful it will be to change course.
US Budget Watch has constructed its own “current policy” baseline by assuming select policies do not conform to current law (see http://crfb.org/blogs/understanding-currentpolicy for details).2 Over the next decade, keeping certain policies in place would result in roughly $3 trillion less in revenues than is scheduled under law and close to $2.5 trillion more in spending, including interest. Complying with current policies without offsetting the costs would result in drastically larger deficits between 2010 and 2019 and would cause the ten-year deficit total to grow from an already dangerously high $7.1 trillion to $12.6 trillion. Debt held by the public would rise to over 90 percent of GDP by 2019, as opposed to 68 percent without those changes.
With public debt accumulating on a compounding basis, extending current policies would create an even more dire long-run picture. CBO’s Alternative Fiscal Scenario, which generally assumes current policy (although it has not been updated to reflect CBO’s latest economic and technical assumptions), projects deficits will rise to 10 percent of GDP by 2027 (rather than 3.6 percent under current law), exceed 20 percent by 2045 (as opposed to 7 percent), and reach 42 percent by 2080 (rather than 18 percent).
Though not technically “current law,” the CBO baseline makes assumptions regarding the growth of discretionary spending that are probably unrealistically low. As a matter of convention, CBO assumes that discretionary spending (including supplemental spending for overseas operations) will grow roughly with inflation. In reality, the discretionary spending level is set annually by Congress, and absent any caps it can grow at any rate. Historically, the growth rate has been much higher than inflation— often closer to the pace of GDP growth.
At the same time, the cost of continuing the current policy of annually increasing discretionary spending is quite high. If regular discretionary spending is allowed to grow with GDP as opposed to inflation, it would add $1.7 trillion to the deficit over the next ten years (excluding interest). Even after assuming a gradual phase-down in spending for the war in Iraq, discretionary spending would still be $1 trillion higher than in CBO’s baseline.
The mounting debt under such a scenario would likely crowd out private investment to a significant degree, resulting in stunted economic growth. At the same time, it would ensure that government interest payments would consume a large and rising share of the budget, leaving little room for anything else. And, at some point, our rising debt would make continued borrowing prohibitive, as our lenders and investors cease their large-scale purchasing of U.S. Treasury bonds. If it came to this, the result would likely be a serious fiscal and economic crisis, followed by steep and perhaps crippling tax increases and spending cuts.