That's a really interesting problem, but falling back on laws to protect you from it seems to be accepting a sub-par solution without having fully explored the issue. This is something that ought to be solved by measurement and corporate culture - if you can properly measure your output, this time-based race to the bottom shouldn't be an issue, it becomes an output-based race to the top, and there's nothing wrong with that, you just bow out of the race when you reach your work-life balance.

Quoting PG on HN is perhaps a bit like preaching to the choir but this is very appropriate: http://www.paulgraham.com/wealth.html

> If one person works late then other people have to match them

or risk being seen as working less hard as that person.

You missed a pretty important bit.