Does tech have a gender pay gap problem?

Survey data suggests that a significant gender pay gap exists among younger tech workers.   This bucks overall trends which show a much smaller gap at the point of entry into the workforce which then widens at around the age of 30, when women are most likely to take on childcare responsibilities. 

It's not clear whether this is a case of failing to pay female workers the same wage for the same jobs - which would certainly be unlawful in the UK - or whether it's a case of the tech industry attributing much higher value to skills in which men traditionally excel.  But with increased scrutiny of gender pay gaps (and a forthcoming requirement for UK businesses with 250+ employees to report gender pay gap data), businesses in this sector need to grapple with the issue, fast.