Abortion is an essential part of a population control program
Let's face it, sometimes contraceptives don't work. And if we ever want to fix the ills of the world, putting an upper limit on the number of people born each year in the world will require that abortion be an option for unwanted pregnancies. Issuing birthing permits by lottery is also a good idea. There can be incentives and disincentives that are effective but not overly cruel. I compare this to the idea of issuing carbon credits, but birthing permits deals with the cause rather than the aftereffects.