The nonpartisan Moment of Truth Project headed by Democrats Erskine Bowles and Alice Rivlin and Republican Alan Simpson issued a report just last month that said the chained C.P.I. won’t cut spending, but instead will limit future growth.

“Since 2000, the chained C.P.I. has, on average, been 0.25 to 0.3 percentage points lower per year than the standard C.P.I. measures. Though this difference is small on average, it compounds over time; depending on which index you use, prices have either increased by 34 percent or 29 percent (chained C.P.I.) between 2000 and 2011. Over a longer time frame, this difference would become even more pronounced,” their report said.

More bluntly, their report quoted Robert Greenstein of the Center for Budget and Policy Priorities, who said: “This change should not be regarded as a benefit cut or a tax increase. It should be regarded more as a technical change to achieve Congress’s stated goal of keeping pace with inflation in as accurate a way as possible.”

Plus, Obama would include financial protections for the poor and elderly, so they would be guaranteed from seeing any decreases.