[nostrademons]

That assumes productivity remains constant, which has historically been a poor assumption, both in the economy at large and with individual people. When you do something a lot and have a modicum of intelligence (and most Googlers do), you figure out new, more efficient ways of doing things. That lets you accomplish more while working shorter hours.

The unfortunate thing is that if you're really good at making things more efficient, people want you to do it all the time, but if you're paid for results (Googlers are) and decent at setting boundaries (by and large Googlers aren't, but this is an individual-responsibility thing), you can work out compromises that give you both professional advancement and time for a life.