The 1970s have witnessed significant changes in the trade policies and strategies of many LDCs. In the 1950s and 1960s most of them adhered to policies of import substitution behind highly restrictive quantitative controls, intensified by overevaluation of the exchange rate with attendant disincentives for export. In the past decade, there has been a marked reduction in the degree of bias toward import substitution. Even in countries where quantitative restrictions and tariffs continue to provide inducements for production for the domestic market much greater than incentive for sale abroad, bias is less extreme than in the past. In other countries, notably Brazil and South Korea, bias has been completely reversed, to a point where one might even claim a bias towards the foreign market and against the home market. This shift in trade policies has resulted from a number of factors, some specific to individual countries, but chiefly because of evidence that the excesses of import substitution were detrimental to growth.