I'm asking just one question (it's in bold). If you treat any sentence with a question mark as another question and thus violating the policy on "focusedness", please steer clear of the text below the sentence in bold.
What impact does the paid vacation leave have on labor productivity? Do employees get re-energized and work better, or is there no such effect (or is it outweighed by 160 or whatever lost working hours)? Are there any studies on that, what are their conclusions? Are American employers stupid or, on the contrary, prudent when they show reluctance to grant such leaves to their employees in the absence of employee-oriented labor laws in the US? Note, I'm not asking whether there is any positive effect of paid vacation leaves generally (on mental health, reported happiness, etc.).