Although the evidence might be somewhat mixed (see below), the argument for women's representation on boards remains a powerful one. Apart from better returns, it's also about fairness. For more pragmatic souls, it's also about the pressures that companies like GXY will be under to face up to this issue. Better to do so voluntarily and make a good choice than be forced to do it and possibly make a less than ideal choice.
https://www.theguardian.com/busines...omen-on-the-board-perform-better-report-finds
http://www.catalyst.org/media/compa...higher-financial-performance-according-latest
https://www.forbes.com/sites/kimels...porate-boards-its-not-good-news/#2dceb5255ecb
http://fortune.com/2015/12/07/female-board-directors-returns/
https://theconversation.com/the-evidence-is-clear-firms-do-better-with-women-on-board-20580
http://law.unimelb.edu.au/__data/as...rporateGovernanceandDirectorsDutiesPaper2.pdf
There is much more research available if you care to look.