Female: -19.5%
No, this is not by Lady Pain (Marta Manso) (cc by)
Women are, like, totally underpaid in the tech world.
Obviously, this is using proxy measures like age and education rather than experience and skill, but it's still a pretty strong statement. After controlling for age, education, specific occupation and even the labour market, there is still a very strong effect showing that women are paid 80 cents on the dollar.