The chained consumer price index, as a measure of inflation, makes a certain amount of sense. It certainly is true that consumers will substitute cheaper goods for more expensive goods when prices increase. Old people like me, whose Social Security payments are not the greatest part of our income, can cut back from shell steak to pork tenderloin; or from 85% lean chopped meat to 70% lean chopped meat; or from fresh asparagus to canned string beans.
The substitution effect makes sense, up to a point. If you're already eating cat food as your primary source of protein, what in hell do you substitute? People actually trying to live on Social Security cannot survive a chained consumer price index.
If Social Security were means tested, I could survive it — but if it were means tested, Social Security would be eroded down to nothing. Nobody really gives a shit about the people who depend on it for their survival. The most important thing about Social Security is that everybody gets it, so even rich people get it (and generally more than poor people do.)
So, if a "grand bargain" comes about, and it includes a chained consumer price index, you should be aware that Obama has sold you out to the fucking plutocrats. Okay, he's looking for a deal. I don't care. We don't need a grand bargain. We need justice.