Uncertainty Forecast Ranges Of CBO's Long-Term Budget Projections

From Congressional Budget Office, "The Uncertainty of Long-Term Budget Projections" Presentation by Ben Page:

CBO’s long-term budget projections generally reflect current law and estimates of future economic conditions and demographic trends. Those projections depend on estimates of the future paths of mortality rates, productivity, interest rates, and health care costs, among many other variables. To illustrate some of the uncertainty about long-term budgetary outcomes, CBO constructed alternative projections showing what would happen to the budget if those factors differed from the values used in the extended baseline.

The Uncertainty of Long-Term Budget Projections from Congressional Budget Office