Average male pay is higher than average female pay for a simple reason. Despite decades of enforced equality, women still have babies, and men still don't. So women who wish to spend any substantial time at all with their own offspring will fall behind in their careers, and their earnings will be less.
I still don't understand why we need a gigantic airport sprawled across South East England. What does it gain us, compared with the misery of noise, pollution and congestion it causes in our cramped country? Would it really be so bad if we had to take a train to Paris or Amsterdam to fly to the U.S.A.?