What are benefits of being bald? Monks are bald because as I read somewhere that when person is bald he looks unattractive and so no one else attract towards it. So what are other benefits to being bald either for monks or layman?
It helps to identify you socially as a monk (as does the uniform clothing), so that people know when they see you, "that person can be identified as a monk".

At the same time it helps to alter, remove or hide your personal identity, e.g. as a person with an individual appearance such as hair color and hair style.

I suppose another practical benefit is that it's also clean and cool (an opposite extreme, for some non-Buddhist sramanas, was to not touch or cut their hair at all, so that it became long and matted).

So far as I know the practice pre-dates Buddhism: MN 26 says,


  So, at a later time, while still young, a black-haired young man endowed with the blessings of youth in the first stage of life — and while my parents, unwilling, were crying with tears streaming down their faces — I shaved off my hair &amp; beard, put on the ochre robe and went forth from the home life into homelessness.