This is a well-researched and thought­-provoking analysis of the 'informal sec­tor' in urban Delhi: a segment of urban economy—which so far has attracted only the 'cursory attention of demogra­phers and social scientists'. The magnitude of this sector in urban Delhi's total employment has been estim­ated by various methods, and it has been found that, right from the fifties, employ­ment in this sector has maintained a share of above 50 per cent of the total and is probably around 65 per cent (about two-­thirds) today. This is significant as well as penetrating when one thinks of the plight of this huge mass of workers with a marginal existence in a marginal sec­tor of the economy marked by low pro­ductivity and uncertainty—unorganized, unregulated and totally unprotected by labour legislation, workers' union, etc. The fact that 74 per cent of the sample population (77 per cent in the case of migrants) belong to the age group 15·39 and another 20 per cent (20.5 among migrants) to the age group 39·59 does not make things any easier. The speedy growth of population of the metropolis (through in-migration) has led to a huge addition to the labour force, creating a supply-demand imba­lance in the organized sector of the work­force. The proliferation of peripheral and marginal activities through a growing informal sector in the urban environment of Delhi is attributed to the rapid surge in its labour force and emergence of numerous service-oriented activities to meet the demands of changing consump­tion and production structures and value systems in a rapidly urbanizing economy. The author, on the basis of a study of the urbanization process in the deve­loping world and in India, observes that the city-ward movement of the people from rural and small urban areas in search of better opportunities (mainly due to rural-urban wage differentiation as postulated by Todaro) is directly responsible for modern urban growth­ specially in the case of large cities. The growing informal sector, due to its easy accessibility; low capital and skill require­ments, can absorb migrants, 'may be with a time lag'. Migration to urban Delhi, as well as to other cities, is a 'rational decision' on the part of the mig­rants, derived on the basis of the well­-knit information network that operates between the places of origin and destina­tion', and the flexibility of the informal sector, while absorbing the migrant ...