Australia's ethnic Australian population is in significant decline, like that of some other civilized nations. (Our decline is slower than that of others, but the bottom line still is: not enough babies born alive.) Consequently, the former Howard government started paying mothers a $5000 "baby bonus" (or more properly a First Child Tax Refund).
Parents are eligible for the payment on compassionate grounds if a baby is stillborn beyond 20 weeks' gestation. Late term abortion qualifies for "baby bonus" purposes. You can guess the rest.
The loophole can't be closed till 2009, because printing new forms is expensive. (link)
People commonly kill helpless, un-offending human beings, innocents who have not wronged them in any way, because they can and they gain by it. The gain can be material, as in an uninterrupted university career, or psychic, as in a sense of control of one's life.
In the Australian "baby bonus" case, the gain is clear cut, and so is the lesson. When there are helpless human beings in the power of other human beings, when there is a way to gain from the deaths of those who can't protest or fight back, and when killing is made legal, safe and as far as possible stigma-free, then killing will ensue. Incentives work.