I believe it could, and I'm sorry I can't put a figure on it for you.
But I strongly believe that making tax policy in a gender-blind way means it's going to be poor tax policy, in terms of achieving the government's own stated objectives, whatever those objectives are, because the government is not using complete information in formulating its policy. And such tax policy will not actually predict how taxpayers are going to respond, because they will respond differently, depending on whether they are men or women. This needs to be taken into account to get the results the government in power wants to get, whatever the government.