The participation rate in the US has declined much less for those at lower levels of education:
That the lower educated are disproportionately supporting employment growth, through lower paid jobs, may help explain why, so far, we have not seen significant wage growth:
The fact that the participation rate of those in the higher-educated bracket has fallen by more may be explained by growing wealth inequality. QE has raised asset prices, disproportionately benefiting the better off who tend own more assets. Overall, they thus have less need to work than those on lower incomes with less assets – often, but not always, those with a lower educational attainment – and who have had low or falling real incomes for several years.