Correcting this comment that unions drive wages down.. Please read this study, link below. The truth is completely the opposite from what you wrote above. The reason that Women in Hawaii are at the top in terms of men's pay, is likely a result of Hawaii being a strong union state, one of the strongest in the United States. Unions bargain collectively for pay raises and better benefits, a force more powerful than an individual employee trying to seek out a raise on their own behalf.  Your point about low wages  is more likely to do with the fact that of Hawaii's heavy reliance on Tourism as the number 1 driver of economy.  Tourism jobs are low paying by nature - servers, housekeepers, bellmen, etc.. Compare that to a place like Washington State where tech is a key driver of the economy. Tech jobs and related jobs pay more than Tourism jobs. 
https://www.bls.gov/opub/mlr/2013/04/art2full.pdf