More speculation than information exists on the reasons large segments of the population are outside the labor force, i.e., neither working nor looking for work. One argument set forth is that many blacks are not labor force participants because they have given up the search; they do not believe jobs are available. The result is "hidden unemployment," or unemployment which studies focusing on the civilian labor force do not consider. The speculations persist because of the absence of national data on labor force nonparticipants. The Bureau of Labor Statistics has recently published the kind of data which could replace guesswork with fact. Using those data, the authors have analyzed the problem of hidden unemployment. They compare the reasons for nonparticipation as these vary by race. The results suggest that the explanations for nonparticipation are not greatly different for blacks and whites. (Author)