This publication is the fourth of four volumes of "Tomorrow's Manpower Needs," which are devoted to the subject of national, state, and area projections of manpower requirements. This volume includes a discussion of the assumptions on which the national projections of industry and occupational requirements are based, and the methodology used to develop these projections. An industry-occupational matrix is presented for 1960 and 1975, consisting of the percentage of distribution of employment by occupation in 155 industries and industry groups representing the entire economy. Other statistical tables are: (1) total national employment by industry, 1960 and projected 1975, (2) total national employment by occupation, 1960 and projected 1975, (3) percent distribution of occupational employment by industry, 1960 and projected 1975. Related publications are available as VT 008 727-VT 008 729. (CH)