This paper surveys recent work on dual economy models starting from the famous Dale W. Jorgenson paper (1961) and ending with some of the new contributions to the literature on N orth-South trade, which have the same analytical structure as the dua l economy model. Various models are compared with respect to assumpti ons about asymmetries, speeds of adjustment, and factor immobilities. Two important conclusions are noted: dynamic behavior is often quite sensitive to the ranking of adjustment speeds and the direction of f urther research should be toward further disaggregation. Copyright 1988 by Blackwell Publishing Ltd and the Board of Trustees of the Bulletin of Economic Research
