I'm reading freakonomics just now. Interesting book, but one point he gets wrong.
He says that parents often badly judge the risk their children are at and cites the fact that more children are killed in swimming pools than are killed by guns each year - but quite a margin. he suggests that when given the option of sending your kid to play with someone who has a gun in the house is actually safer than sending them to a house where a swimming pool can be found.
Fine - directly compared to each other this is clearly the case. However, he misses the context. Let's aggregate the typical possibilities for harm to come to a child in a house with a large swimming pool and compare this to the aggregate of possibilities of a child coming to harm in a house with a gun in the drawer. So, in general it is more likely a kid whose parents have a gun lying around have a bunch of other things going on too - drugs, abuse, dangerous things lying around etc.... I don't have any hard stats, only common sense (and do i even have that!?), but i know where i would feel less comfortable leaving my child.