Freakonomics by Steven D. Levitt and Stephen J. Dubner

Morality is how we want the world to work. Economics is how the world actually works. Abortion reduces the crime rate. Taking your child to museums won't keep them off drugs. Guns don't kill people, swimming pools do.

Freakonomics is a study in comforting lies and unintended consequences. It reveals a world which at first glance appears counterintuitive or chaotic, but is in fact driven by incentives which you can tease out by asking the right questions of the data.

What's made this book a big hit is the range of systems it looks into - cheating by sumo wrestlers, weird baby names, the history of the Klu Klux Klan and dealing crack. It's all about getting information, collating it and finding out what's happening.

So there's a lot of light-hearted stuff here (crack and the KKK are funny, right?) but there's some in depth looks at big issues - bringing up your children for instance. It turns out parents have a big influence on the future success of their brat, but it's all stuff which happens before the birth - income, education level, etc. None of that endless fussing seems to make much difference. Even whether parents are still together or not isn't a big deal.

Of course, this is a book about using statistics to look at complex systems, and there's always going to be questions over how you use the data. There's been a big stramash over the authors' assertion that legalised abortion caused a steep decline in the crime rate seventeen years later. That's been criticised heavily on economic as well as moral grounds. The most interesting accusation is that Levitt whitewashed his earlier finding that a higher rate of abortions by black mothers-to-be in US cities was in fact the important factor in the crime drop. Now if that's true, what happened to economics over morality?

Anyway, it's always a very interesting read, and a great reminder not to put your faith in received wisdom and wishful thinking.

PS christ knows what I've done to the font. I actually posted this to Advance With Sound by accident, then had trouble getting it back. Now it's all wrong.