Changes in the distribution of job skills in the U.S. economy between 1960 and 1976 are examined in this document. The research assesses the effects of changes both in the distribution of employment among different occupations and in the skill requirements of individual occupations. Estimates of the latter component are based on two editions of the "Dictionary of Occupational Titles," the third edition (issued in 1965) and the fourth edition (issued in 1977). The results indicate that the general skill requirements of jobs have changed little over the past decade and a half, a period of growth and technological development when the supply of skilled labor increased dramatically. (Author/PGD)