Dualism is a concept widely discussed in development economics. It represents the existence and persistence of increasing divergences between rich and poor nations and rich and poor peoples on various levels. Specifically, the concept of dualism embraces four key elements as stated by development experts.
Different sets of conditions, of which some are “superior” and others “inferior”, can coexist in a given space. Examples of this element of dualism include Lewis’s urban and rural sector dualism, the coexistence of wealthy, highly educated elites with mass of illiterate poor people; and the dependence notion of the coexistence of powerful wealthy industrialized nations with weak, impoverished peasant societies in the international economy.
This coexistence is chronic and not merely transitional. It is not due to a temporary phenomenon, in which case time could eliminate the discrepancy between superior and inferior elements. In other words, the international coexistence of wealth and poverty is not simply a historical phenomenon that will be rectified in time. Although both the stages-of –growth theory and the structural-change models implicitly make such assumptions, the facts of growing international inequalities seem to refute it.
Not only do the degrees of superiority or inferiority fail to show any signs of diminishing, but they even have an inherent tendency to increase. For example, the productivity gap between workers in developed countries and their counterparts in most LDCs seems to widen with each passing year.
The interrelations between the superior and inferior elements are such that the existence of the superior elements does little or nothing to pull up the inferior element let alone “tickle down” to it. In fact it may actually serve to push it down-“to develop its underdevelopment”; (Hans Singer 1970:60-61.).