Should the NHS bribe people into leading healthy lives? Should there be cash incentives paid out when people eat less junk food, quit smoking, drink less alcohol etc? In a BBC News Channel debate with Mark Littlewood, LSE health economist Zack Cooper rejected the charge that there was anything patronising about these proposals. He quoted survey evidence showing that the vast majority of smokers want to quit, but very few do it. So, far from forcing other people’s preferences upon them, this was merely helping them to act in accordance with their own preferences.
The mismatch between what smokers say in surveys and what they do in practice is a classic example of the difference between “stated preferences” and “revealed preferences“. Social engineers love stated preferences. Opponents of big supermarkets, too, always have a survey at hand, indicating that the vast majority of residents in their areas would never set foot in a discounter. But once it is there, it flourishes.
There is nothing schizophrenic about this behaviour. When asked whether you would shop in a big supermarket in your area, of course you respond something like “No! Small, local shops are much more charming and personal” – because that is the socially acceptable thing to say. When you smoke, saying that you want to quit makes you at least a repentant sinner.
Evidence for this effect can be derived by comparing expenditure surveys to national accounts. For most goods, the two show broadly the same pattern: with small errors, what people profess to buy grosses up to what is really being sold in the country. But tobacco is a big exception. Less then half of the recorded cigarette purchases shows up in the Living Cost and Food Survey. In the US equivalent, the ratio is not even 40%.
So whatever the arguments for healthy-living bribes may be, people’s “preferences” cannot be counted among them.