[bitshiftfaced]

Wouldn't the marginal risk from the blood test be zero, since they do a little blood prick on their foot anyway?

Also, there's a second order effect you're ignoring: a mandated paternity test would change expectant mothers' behavior leading up to the birth. You wouldn't try to dupe someone if you knew you'd be found out. Or, if you weren't sure, you'd more likely be transparent.

[mcphage]

> Wouldn't the marginal risk from the blood test be zero, since they do a little blood prick on their foot anyway?

The source of risk isn't performing the test, the source of risk is the father getting upset and killing the mother and/or child.

[bitshiftfaced]

I did some looking, and it's so rare that there aren't any go-to statistics to cite. There are some reports of men committing murder after a paternity test, but it's unclear to me how what you're saying is anything more the speculation.

It might actually be that mandatory paternity tests reduces the background rate of familicide. All of the reports that I could find were only after the father had invested considerable time into raising the child as their own. The stakes of the deception are much higher. But if they know the day the baby is born (or earlier), then it's much easier to walk away. It also makes it pointless for the deception to happen in the first place.