Does gun control mean fewer guns on the street and less violence? Does encouraging gun ownership mean better protected people and less violence?

I don't think it's too early to be asking questions like this. When you're faced with a tragedy like what happened today at Sandy Hook Elementary School, it's reasonable to start asking questions about violence prevention. It's part of the bargaining stage of grief — wondering if there's something we could have done that would have prevented all those needless deaths. And let's get one thing straight: Everybody wants to prevent what happened today.

So what can be done about it? And what does the science say?

I've been trying to get a handle on that for the last hour or so and here are three things it seems we can definitively say:

• It would be completely accurate for someone to tell you that studies in places like Australia and Austria found that implementing more stringent gun control laws reduced deaths from gun-related suicides and violent crime.

• It would also be accurate to say that a study of the effects of the Brady Handgun Violence Prevention Act in the United States showed no big reductions in gun-related deaths, except for suicides among people older than 55.

• And it's also true that a 2003 study of conceal-carry laws in Florida found that they seemed to make no difference one way or the other — neither increasing nor reducing rates of violent crime. Read the rest

The National Breast Cancer Coalition has come out with new evidence-based position statements regarding several popular preventative and treatment options for breast cancer. Among the findings: There is no link between abortion and breast cancer; there's no evidence that breast self-exams actually do anything useful; and the policy of routine mammograms for every woman doesn't help as much as we think it does. Read the rest