The gender gap may be in clothing. Look at any ad or go into any place of business and tell me that a man in dress slacks and a nice shirt, doesn't look 50% more prepared to be an executive than a woman in slacks and a shirt/sweater showing cleavage. Ladies, if you mean business, then dress like it. Don't dress for a picnic if you want to be on the board.
Yesterday I was in 3 places of business. Observed working women in jeans and sweat pants. I saw no men dressed like that. It's not a salary difference, but goals. I'm not asking for girdles and high heels the way we did in the 1960s even at entry level, but just a little pride and modesty.
Twenty years ago I suggested to a 20-something clerk that she not wear jeans to work (in the veterinary medicine library). She was quite insulted (although it was a written policy by the library manager above me), and said she didn’t have time to dress nicely for the job. So I suggested she prepare her clothes the night before. She soon left for another job. Which was fine, because she also didn’t want to arrange the serials for binding in alphabetic order.