A debt crisis is coming. But don’t blame entitlements.

There is some room for additional spending reductions in these programs, but not to an extent large enough to solve the long-run debt problem. The Social Security program needs only modest reforms to restore its 75-year solvency, and these should include adjustments in both spending and revenue. Additional revenue is critical because Social Security has become even more vital as fewer and fewer people have defined-benefit pensions. Medicare has been a leader in bending the health-care cost curve. Reforms to payments and reformed benefit structures in Medicare could do more to hold down its future costs.

As we focus on the long-run fiscal situation, our goal should be to put the debt on a declining path as a share of the economy. That will require running smaller deficits in strong economic periods — such as the present — to offset the larger deficits that are needed in recessions to restore demand and avoid deeper crises. Last year’s Tax Cuts and Jobs Act turned that economic logic on its head. The economy was already at or close to full employment and did not need a boost. This year’s bipartisan spending agreement contributed further to the ill-timed stimulus. The Federal Reserve will have to act to make sure the economy does not overheat.