That's not a particularly useful statistic. How much of that 42% is kids 16-18 in high-school, people in college 18-22, people in grad school 22-25, the retired?
Together that's roughly 70 million people who are mostly being counted in your "unemployed" figure that shouldn't be included.
That's not even including women who don't work. There is still a delta of ~13% b/w male and female labor force participation rates. They're 122 million women age 16 and over in the US. That's probably another ~10m who shouldn't be included in your unemployed figure.
The above estimates double-count: those enrolled in school who work, elderly who work, etc, but is much more realistic than your figure.
You have a point there, but I wouldn't be quite so sanguine. Look at the different participation rates of graduates and those without a HS diploma. The difference is huge, and I think it tells us something about the real unemployment rate.
Another issue is that those counted as employed include a large number of underemployed, i.e people forced to work part time because they can't find more work.
You do a good job of segmenting the population of unemployed people in to various groups, but you make not even a single argument for why they shouldn't be counted as unemployed.
For instance, you say, "women who don't work ... shouldn't be included in your unemployed figure." Why not?
In 2006, ~30 million people were enrolled in the final two years of HS, college, or graduate school: http://www.census.gov/prod/2008pubs/p20-559.pdf
Adjusted for demographic trends, that's probably higher now.
In 2009, about 12.9% of the population was over 65: http://quickfacts.census.gov/qfd/states/00000.html
Together that's roughly 70 million people who are mostly being counted in your "unemployed" figure that shouldn't be included.
That's not even including women who don't work. There is still a delta of ~13% b/w male and female labor force participation rates. They're 122 million women age 16 and over in the US. That's probably another ~10m who shouldn't be included in your unemployed figure.
The above estimates double-count: those enrolled in school who work, elderly who work, etc, but is much more realistic than your figure.