Behind all the slogans and initiatives around gender equality are vast stores of equity partner profits, concentrated in the hands of men. 

Ask any law firm leader and they'll tell you that gender parity is high on the agenda. Targets set, initiatives launched, PR strategies carefully devised. But much of the progress we've seen lately evades one of the things that matters most: the number of women with a share in the equity. 

Despite this modern era of transparency in which firms have started to disclose once-sensitive data on their pay gaps among women and, to a lesser extent, ethnic minorities, many still keep schtum on the equity. Most of the U.K.'s top 10 firms refused to disclose the gender divide at equity level when asked by Legal Week.