Originally Posted by Supple Cow

A man never has a right to make the ultimate physical decision about having a baby, but he always has a responsibility to pay child support for it if the woman decides to have it. The woman always has the right (let's hope) to make the ultimate physical decision about having a baby, but she does not always have the financial responsibility for it because she can always sue the man for child support. This system has a built-in incentive for women who don't have physical concerns about having a baby to behave irresponsibly about birth control.

...It merely recognizes that women should also behave responsibly and protect herself when choosing to have sex. The current system just gives men a lot of reason to distrust women.