Internal Migration and Urban Employment: Reply
回应Todaro对Cole-Sanders迁移理论的批评，指出双方分歧在于对城市非正规部门的不同看法，并强调迁移者可能以非正规部门为永久就业目标，从而质疑Todaro模型的普适性。
Despite diversity and intensity of Michael Todaro's comment (1986), essence of controversy reduces to differences in respective views of urban subsistence sector. Each view, in turn, depends upon a distinctive viewpoint. Observing from viewpoint of bureaucrat and other elite to whom he defers in his comment, Todaro sees large cityward flow of Third World humanity as a menace, destroying urban amenities. Todaro's focus being modern sector, his model only incorporates an urban subsistence sector indirectly, and then only as a way station on route to modern sector employment. His assumption is that every potential migrant has modern sector employment as an explicit goal.' Conceptually, he leaves no room for uneducated rural persons whose aspirations are keyed to modest employments of urban subsistence sector. We, on other hand, look from below, from subsistence sector. From there, we see both rural and urban welfare gains from observed spatial movement of labor. We grant that unpleasant externalities may be involved, especially from point of view of a discomfitted elite. However, those possible externalities should be studied in their own right and have no place in a debate between competing explanations of migration.2 The present debate, therefore, comes down to a straightforward empirical question. If, in fact, there are persons who move to city with intent of taking up permanent employment in urban subsistence sector, then their decisions cannot be explained by Todaro. If they are few in number, theorist may assume them away. If their numbers are significant, however, migration flows must be viewed as dual in nature and an alternative explanation for subsistence portion is required. Todaro's crucial point is that the ColeSanders' theory requires them to make an artificial separation of migration flows into those who go to modern sector and those who go to and remain in subsistence sector. This argument is effectively countered, we believe, by our crucial point that Todaro's view of an undifferentiated flow carries with it inappropriate assumption that all migrants deem themselves able to enter into modern sector employment.3