I once negotiated with an employer that tried to use these exact kinds of cost-of-living stats to compute an adjusted "matching" offer to an offer from Californ

I once negotiated with an employer that tried to use these exact kinds of cost-of-living stats to compute an adjusted "matching" offer to an offer from California. But it's a bad deal because those high california prices are "paying" for very desirable benefits like nice weather and job opportunities. These differences are not considered when "living" is treated like a commodity where the only stat to compare is cost.