I would argue that more professional dress inspires more professional
behavior. As an example, I'd point to the NYC "graffitti" cleanup
under Guiliani, and the corresponding crime rate drops.

I think this is oranges and grapefruit, and an example of selective
data. Guiliani did many other things at the same time, and it may well
be that it was those other things that reduced crime. What crime in ATC
are you aiming to reduce?

Turn it around, how does it impact safety by not letting them take naps?

Studies have shown that napping improves performance after the nap. (In
some political jobs, it arguably improves performance during the nap.
It is my understanding that air traffic control is a stressful job,
and that's one of the reasons scope time is limited. Anything that
would improve alertness while at the scope would be good. Naps do that
with no down side.

Jose
--
There are more ways to skin a cat than there are cats.
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