I worked in tech for years (still do as a freelancer but I'm trying to pull back). I can confirm, absolutely, that women make less in the kind of work I do (software development).

There are also a lot fewer of them than men, and I really don't think it's because there's as much of a lack of them trying to get through the door as the men who (usually) make the hiring decisions try to pretend there are.

There are fewer, for sure, but I also think they run up against bro culture, at least here in America. I've been fortunate to work with companies that are a bit more open to women (PayPal and Pearson), but I've heard stories at those companies from women who get there that they simply don't even get past the door in many tech firms. I can't attest to that, of course, since I'm not a woman, but the stories are pretty consistent. There's no reason not to believe them. I hope that it has gotten a little better since my full time days. I've been running into quite a few of them while I've been freelancing, which has been a pleasant surprise. Good luck!