Wouldn't it also exaggerate any current increase in real wages? Would there be any increase in real wages in the past year if the CPI was computed under the old system?
Probably "yes." Here's why:
If you used "old" CPI methodology, you would get a 0.5% reduction in estimated real wages. But a 1% tax cut swamps that.
I don't think this is worth arguing about. Whether it's up or down a half a point may make it possible for one set of protagonists or the other to beat their chests and crow "It's up!" or "It's down," but what the Hell really is the difference between minus half a percent or plus half a percent? We're talking 130 bucks a year or something like that. BFD.
The real issue is that during the 1970's, when average wages were supposedlly so "high," most of the increase was being eaten up by taxes. The actual wage earner barely saw half of it.