Now It's Time for the Group Hug (Author One-on-One: Tim Harford)
Like Dan, I have enjoyed this discussion very much, and I hope that's true of Omnivoracious readers. It has been hard work--in a good way--and forced me to think carefully.
Let me finish by writing a bit about a subject I've been thinking about recently--it might help us find a bit of common ground and show why this discussion is important. Let's think about the problem of climate change, which is widely believed to require us to cut back a lot on our emissions of carbon dioxide. So what should we do?
Standard economics has a solution: a carbon tax, or a tradable permit scheme, to raise the cost of emitting carbon. We'd all have an incentive to cut down by driving less and turning down the heating or air conditioning, and also by insulating our homes and finding more efficient cars and fridges. Businesses would also cut back, and would have an incentive to develop new technologies.
Behavioral economics draws attention to different considerations. For example, we're not as smart as conventional economics assumes, which means that we might fail to notice ways to reduce our energy bills. We might also need to be reminded about what our neighbors are doing: psychologist Robert Cialdini showed that we're more likely to recycle if we think everyone's doing it. That may hold true for carbon-saving too. And although we're reminded of high gas prices every time we fill up, we really need to be reminded of them when we're buying a new car or a new fridge.
So which approach is right? That's a strange question. They can both be right, and I think that they both are.
Of course, the economic incentives will work. I don't think there's any serious doubt that raising the price of carbon would persuade us to pollute less. The Logic of Life showed that we are sensitive to these simple incentives in the most unexpected situations. For instance, raising the risk of unprotected sex persuaded American teens to have more oral sex instead; and two Australian economists, Joshua Gans and Andrew Leigh, have found that tax incentives can persuade pregnant women to delay labor, and even deter people from dying too quickly. (It's really true: the death rate in Australia dropped in the week before inheritance tax was due to be abolished, and then sharply rose the week immediately after. A lot of people were clinging on to life to avoid their estates being taxed.) If people will change their date of death or the day they have a baby in response to a tax incentive, I am quite sure that they will be more environmentally friendly, too.
But I am also sure the behavioral insights will produce results. Cass Sunstein and Richard Thaler report one dramatic success: people cut back dramatically if the electricity company gives them an "Ambient Orb" that glows red when they're using a lot of power. There's no standard economic theory that explains why that should be; and that is just one example.
So we need insights from both economics and psychology to make the world a better place. And I know that Dan will agree with me when I say that whatever we try, we should be checking carefully to see whether the idea is working as predicted, because the world is full of surprises.
Thanks to all Omnivoracious readers for dropping in on our debate.
Your logical friend,
Tim Harford



Dear Reader,
When it comes to making changes in the world, such as laws, policies, or even business and individual practices, standard economics assumes/claims that it can provide the correct and complete answer. The answer! After all if people are rational then what else is there to take into consideration? This is what welfare analysis and the Chicago school of economics is all about. This is also what bothers me about economics, and what I would like to change. If it were up to me, economics would remain as it is in terms of an academic discipline, but we would consider other perspectives, including behavioral economics, when making recommendations for implementing changes in the world. Moreover, I want us to take to heart one of the main lessons of behavioral economics--that our intuitions are not always correct. By doing so, instead of just implementing a policy based on our intuition, we should first experimentally test our ideas to ensure that we are getting what we expect.
Dan, thanks for the kind comments about
So, how is The Logic of Life different in the way it approaches this topic? I take a bird's eye view of the whole controversy over the so-called "teen oral sex epidemic"; I find out that, behind the hype, yes, teenagers are having more oral sex than they used to. But I also find that they are losing their virginities later and are more likely to use condoms. That isn't so much an oral sex epidemic as a safe sex epidemic. I argue, informally, that this would be a rational response of a typical teenager to increased education about pregnancy and particularly to the now near-universal knowledge of the threat of HIV/AIDS. (You can read a short article I wrote about all this in
Let me give you an example. Imagine that I described to you some puzzles of different sorts that required memory, concentration, thinking, and creativity. Suppose I then asked you to predict how well people would perform on these games if they were promised a payment that depended on their performance. I would also tell you that for some people the payment was equivalent to 1.5 days of their income, for others it was equivalent to 2 weeks of their income, and for a third group it was equivalent to 6 months of their income. Who would you predict would do the best? If you are anything like the real participants in our experiments, you would predict the third group--the one with the highest pay--would have the highest level of performance.