ABSTRACT
T H E T R A N S I T I O N from a peasantagrarian economy to an urban-industrial one, representing as it does an enormous gain in per capita productivity, cannot be accom plished without profound social changes. One of these changes, the alteration of the class structure, deserves special attention be cause it involves the entire incentive system of the society. Since, however, the subject is too broad for a brief treatment, we wish to concentrate on one particular aspectthe role of vertical social mobility-which we regard as the most crucial. In doing so, we shall try to bear in mind that what is required for accomplishing a major step in socio-economic development may be differ ent from what is required for maintaining the new stage which that step produces. We are concentrating in the present paper on the role of vertical mobility in the process of economic development. Such develop ment in contemporary times, generally re ferred to as the Industrial Revolution, is by no means merely technological; i t is the greatest and most rapid social transformation ever known.
