> Thinking about your primary job: On average, how many hours do you work per week?

Not really sure they are measuring what they think they are measuring. This being more pronounced amongst young people may be because working long is being seen as less and less cool, as there has been a major vibe shift among young workers regarding their relationships with employers. Doesn't necessarily mean they are actually working less, might mean they don't want to admit it.

Revealed concrete hours would be much more trustworthy