Democrats are pleased with the CBO’s preliminary score of the reconciliation package. Adding the cost of higher insurance subsidies, extra spending on Medicaid, and other outlays, then subtracting Medicare savings and new revenues yields a $138 billion reduction in the ten-year deficit, says the agency. That is better than many had expected.

I don’t question the competence of the CBO’s analysts, but I wouldn’t bet my 401(k) on these numbers turning out to be even roughly correct. The uncertainties lie in both directions. The plan might save more money than the CBO says: it has scored the efficiency-promoting experiments conservatively. The bigger risk is that the provisions yielding the projected savings and tax increases will be reversed before they take effect. I would need to think about it, but I might be willing to bet my 401(k) on that.