00690cas|a2200157 i 450000500170000000800410001703500150005810000230007324501270009626000920022330000130031549000310032865000330035965000390039281001010043120260817162806.0090501s1981    us  uzm rtt  00|  a1eng d  a.b100863651 aPorter, Richard C.10aApartheid, the job ladder, and the evolutionary hypothesis :bempirical evidence from South African manufacturing, 1960-77  aAnn Arbor :bCenter for Research on Economic Development, University of Michigan,c1981  a34, 4 p.1 aDiscussion paper ;vno. 95 0aEmployment (Economic theory) 0aEmployees, Rating ofxSouth Africa1 aMichigan.bUniversity.bCenter for Research on Economic Development.tDiscussion paper ;vno. 95