However, the question becomes if men retire earlier.
And the answer is no. [1] Women retire earlier than men on average (at least in Canada. Don't have stats handy for anywhere else, unfortunately). And that's measured in years, more than compensating for the above.
Regarding disabled people, a simple answer is that society as a whole would be against it, as there is enough of a chance of any individual person becoming disabled that it is in their best interest to not allow such a law.
And making an argument from an economic as opposed to a moralistic point of view does not make one a sociopath. As you may not have noticed, I never mentioned my moral point of view on the matter, as it's irrelevant.
[1] http://www.statcan.gc.ca/pub/71-222-x/2008001/sectionm/m-age...
[2] http://www.prdh.umontreal.ca/BDLC/data/can/mltper_1x5.txt
[3] http://www.prdh.umontreal.ca/BDLC/data/can/fltper_1x5.txt
[4] http://www.statcan.gc.ca/pub/11-008-x/2012002/article/11697-...
Yes, making an argument involving decisions that affect the life chances of human beings and hiding behind "economic theory" is sociopathic.
That assumes that only insurance-based risk affects economics.
But for some reason you want to conveniently ignore all these facts and instead point to maternity leave and say that's why we should pay women less? Think again.
But further, if your weren't trolling, the answer to your question is that even if the assumption were true, to pay them less would be sociopathic. That's why it's wrong. Again, think.
If disabled people are actually, objectively, less productive workers, a drain on society, why is it wrong for societies to euthanize them?