Can I clarify a few point about lone parents and gun crime?
I was worried by Ross's comment that "those involved with gun crime tend to have grown up fatherless" because some would infer from this a strong causal link from single parenthood to crime. Such an inference, I feared, would lead to three problems:
1. It would encourage the stigmatizing of single parents, the vast majority of whom are doing a fine job.
2. It would lend a spurious justification to tax breaks for married couples. Politicians would justify these on the grounds of social policy - encouraging families to stay together - rather than recognize them for what they are - hand-outs to the median voter.
3. It might lead to policies to compel fathers to stay in dysfunctional families. This would give kids bad role models, and lead to many being brought up in violent homes; for me (and I suspect countless others), it was a good thing that my dad left home.
Cameron seems not to be committing the first error. But he is committing the second and third.
Now, Daniel Finkelstein and several commenters point out that my rough calculations are consistent with the proposition that people from single parent families are more likely to commit crime than ones from two-parent ones. I never meant to disagree. But:
1. We're talking low odds. It's true that a 12-1 horse (to take Danny's hypothetical number) has more chance of winning a race than (say) a 50-1 one. But equally, neither has very much chance of winning. Mark, in a comment on my post, makes a nice analogy here. Even if only a tiny fraction of skiers break a leg, he says, it's still true that skiing leads to broken legs. I agree. But equally, it's the case that the risk is so small that skiing is a perfectly reasonable thing for people to do.
2. It doesn't follow that single parenthood causes crime. As Mark also points out, it might be that the sort of man who fathers a child and leaves home is irresponsible and reckless. If his children inherit these traits, they might become criminals, without there being a causal role from family structure to crime.
This point bears upon Danny's hypothesis that "reducing single parenthood would reduce gun crime." It's not necessarily true that all ways of reducing single parenthood would reduce crime. If this point, and point 3, are right, we wouldn't reduce gun crime by compelling fathers to stay with families. But we might reduce it by stopping such men fathering children in the first place; I have no problem with a Pigouvian tax upon such men.
There's another reason why I don't want to focus upon single parents here. It's too easy an answer.
Economics tells us that people commit crime because the benefits exceed the costs. This suggests that a bigger cause of crime is the combination of the collapse in demand for unskilled work and the awful education of poorer kids - which make legitimate ways of earning money hard to find - and the high aspirations encouraged by capitalism and celebrity culture.
Insofar as it focuses upon single parents, the stupid party therefore acts like a bully, attacking the vulnerable whilst cringing towards power.
As I asked, has Cameron really changed since he was in the Bullingdon?