I got into a bit of a back-and-forth with Harold Ford on “Morning Joe” today over entitlements. Ford said he “didn’t like my math,” but the question with math, of course, is not whether you like it, but whether it’s right.

So let’s check it out. Start with Social Security: I said that the size of the shortfall over the next 75 year is 0.7 percent of GDP. You could pretty much wipe that out by allowing the payroll tax to apply to wages over $107,000 (Ford seemed to think the payroll tax applies to earnings up to $116,000 now, but he’s wrong about that). CBO estimates “the 75-year actuarial balance [of Social Security] to be 0.6 percent of gross domestic product.” I’ve seen 0.7 percent of GDP elsewhere, but I’ll take that as a slight strike against me.

As for eliminating the payroll tax cap do, “this option would improve the 75-year actuarial balance by 0.6 percentage points of GDP and extend the trust fund exhaustion date to 2083.” Come 2083, you’d have to do something else to shore up Social Security. But I’d be pretty happy to secure Social Security for the next 75 years. Rep. Ted Deutch, incidentally, has legislation to do exactly that.