An analysis of existing data on youth unemployment was used to (1) review the reasons for high and rising youth unemployment, (2) account for high youth unemployment in 1966, and (3) measure the importance of the various causes of rising youth unemployment. Summary findings included--(1) Relatively high rates of youth unemployment are to be expected even in years of low general unemployment because of the large amount of movement into and out of the labor force resulting from the extended period of education characteristic of the United States, (2) In 1966, between three-fifths and seven-eights of youth unemployment arose from inexperienced and reentering job seekers, (3) Rapid increases in the size of the youth labor force and the proportion enrolled in school has led to increased proportions of youth seeking part-time and summer jobs, (4) There is no evidence that employers have become more restrictive toward young job seekers, but they have become increasingly selective among youth, with the result that unemployment rates of the youngest age groups, nonwhites, and girls have increased more than others, and (5) Insufficient vocational guidance, lack of information, and the seasonal pattern of enrolled job seekers entering and leaving the labor force contribute to high frictional unemployment. High economic growth rates, modifications in minimum wage standards, and job creation are recommended to relieve youth unemployment. (ET)