Inequality and Work Hours
But as I suggested in the comments, the association between inequality and work hours might also be explained by the backward-bending labor supply curve. Unlike other goods, the supply of which will increase indefinitely as the price increases, labor carries an inherent disutility. The laborer may increase his work hours to a certain point in response to increased pay, until he reaches what he regards as an ideal standard of living; after that, he may instead see further pay increases as reducing the number of hours he has to drag himself into his job to maintain that standard of living. In societies with high income disparity, the majority work longer hours because they have to. On the other hand, an increase in hourly pay might simply mean fewer hours have to be worked to produce the same standard of living. If cheap credit for starting up self-employment ventures were available, and the interest rates on mortgages and credit card debt were lower, considerably more people might be cutting back their work hours to part-time or retiring early.
There are reams of quotes available from the employing classes of Britain during the enclosures (see here for some of them), arguing that laborers couldn't be forced to work hard enough unless they were made destitute. When laborers had independent access to the means of subsistence, they worked at wage labor only seasonally, for supplemental income; they could afford to rely on subsistence farming for long periods, and go back to working for a boss only when they felt like it.