preliminary results please do not cite geographic concentration in the us retail and wholesale sectors shawn d klimek center for economic studies bureau of census pennsylvania state university david r merrell carnegie mellon november 8 1999 __________________ we would like to thank seminar participants at very helpful suggestions all conclusions here are those authors represent opinions or official findings 4700 silver hill road stop 6300 washington plaza ii suite 211 dc 20233 sklimek ces gov 5000 forbes avenue h john heinz iii school public policy management research data room 238 pittsburgh pa 15213 dmerrell andrew cmu edu introduction when looking landscape one can point a number instances where it appears that industries locate same regions high technology seem be located silicon valley automobiles detroit financial new york chicago tires dayton