http://issues.org/33-1/the-importance-of-middle-skill-jobs/
A recent international survey of adult skills by the Organisation for Economic Co-operation and Development’s Program for the International Assessment of Adult Competencies demonstrates the problem. The survey assessed the proficiency of adults from age 16 to 65 in literacy, numeracy, and problem solving in technology-rich environments. The most recent published report includes survey data on more than 165,000 adults in 22 of the organization’s member countries and two partner countries. It revealed that skills have a major impact on life chances: lower-skill individuals are increasingly likely to be left behind, leading to greater inequality in income. Having lower basic skills also impedes the ability of individuals to gain more education or training when demand shifts toward industries or occupations that require additional competencies. Finally, those with lower skill proficiency tend to report poorer health, lower civic engagement, and less trust.