>You could just use BLS local-area CPI figures, right? I know they have them
>for metro areas, maybe they have state data too.
They just do them for about 20 metro areas, and not in much detail. A real PPP exercise is a lot of work, comparing prices on anywhere from several hundred (in very poor countries) to several thousand (in very rich contries) items. For a quickie descrip, see <http://web.worldbank.org/WBSITE/EXTERNAL/DATASTATISTICS/ICPEXT/0,,contentMDK:20118247~menuPK:299187~pagePK:60002244~piPK:62002388~theSitePK:270065,00.html>.
Doug