Casey Mulligan calculated average work-hours by age. He compared 2007 to 2010:
Seniority layoff practices would tend to reduce hours worked most for young people because, naturally, they tend to be employers’ more recent hires. You might think it would make sense for employers to retain their most experienced workers, but downsizing employers tend to offer and encourage early retirement to people in their 50s and early 60s, who are paid more than recent hires and are starting to think about leaving the workplace.
Yet the chart does not show especially large declines in hours for those age groups (nor can seniority practices by themselves explain why the elderly end up working more).
The Dish 