"As bad as they are, these figures dramatically understate the true extent of unemployment. First, they exclude anyone without a job who is ready to work but has not actively looked for a job in the previous four weeks. The Bureau of Labor Statistics classifies such workers as “marginally attached to the labor force” so long as they have looked for work within the last year. Marginally attached workers include so-called discouraged workers who have given up looking for job-related reasons, plus others who have given up for reasons such as school and family responsibilities, ill health, or transportation problems.
Second, the official unemployment rate leaves out part-time workers looking for full-time work: part-time workers are “employed” even if they work as little as one hour a week. The vast majority of people working part time involuntarily have had their hours cut due to slack or unfavorable business conditions. The rest are working part time because they could only find part-time work."