I like your attitude towards this.

One should try to create a study to investigate the effects better.

As alternative to "6pm you guys all go home, period.", there is likely a difference between "6pm you all go home, but if you really must finish sth, I'll wait until 6:30pm to pull the plug" and "go home whenever you want" (which may end up being 8pm or 10pm and in a game theoretic setting may lead to later and later time).