It's become fashionable in recent years to blame high unemployment on "skills-mismatch" which is wrong, and it's also fashionable in education reform circles to make some overstated claims about the absolute centrality of schooling to improving poverty outcomes. That in turn has created a kind of backlash where some folks react with fury to any observation about the enduring importance of education and human capital. But via Doug Henwood here's a new report from the OECD on adult skill levels in different developed countries that shows the United States isn't doing very well.
This is overblown as an explanation for unemployment since given adequate demand-side policy almost everyone should be able to get some job. But it matters quite a lot for the quality of jobs and the levels of opportunity provided. Having basic math skills might be the difference between being able to cook at a restaurant or cut hair at a salon and being able to parlay that experience into a managerial or entrepreneurial role. Literacy is absolutely key to moving up the value chain in a wide range of workplace situations where you might need to be able to communicate effectively with customers or people above or below you in the hierarchy.
One should also note that skills (or lack thereof) also matter politically. It's harder to screw over people who can do math. It's easier to organize in defense of your interests if you can communicate clearly in writing. Education isn't everything, but it's awfully important both directly and indirectly.