The federal government is confronting significant and fundamental budgetary challenges. If current policies are continued in coming years, the aging of the population and the rising cost of health care will boost federal spending, as a share of the economy, well above the amount of revenues that the federal government has collected in the past. As a result, putting the federal budget on a sustainable path will require significant changes in spending policies, tax policies, or both. The task of addressing those formidable challenges is complicated by the weakness of the economy and the large numbers of unemployed workers, empty...