Professor Ian Walker:

I will jump in here, if I may, because I want to very strongly endorse what Professor Lunn just said. I really strongly agree with this. The anti-littering campaign of a few years ago which I spoke about a moment ago, used classic nudge techniques. It deliberately used classic nudge approaches, which completely backfired and increased the amount of litter people were throwing out of their cars. Critically, you have never heard about that study because it did not work and therefore, has not got out into public awareness. There is a survivor bias towards the nudging studies, in that people hear about the ones that happen to work and the ones that do not work are not heard about and consequently, it might look as if the approach is more successful than it really is. I can actually talk for hours about nudge so I am going to have to keep myself off that topic for any longer.

Just a brief note about defaulting, if you look at any city street, the default way of travelling is to walk and yet most people are not doing that. Most people are spending large amounts of money, time and effort in order to drive a car, therefore maybe defaulting is something we should be a little more cautious about. With energy tariffs in particular, which is something I have worked on, it is actually really complicated. We did some work about three years ago looking at the potential for energy tariffs to help people shift the time of consumption away from peaks, which is something there is a lot of interest in at the moment.

We would really like people to shift their consumption away from the 5 o'clock to 8 o'clock period. What we found when we asked people to work with prototype time-of-use tariffs was that there are so many structural and, especially, social barriers. People were very reluctant to consider changing the times of their consumption in response to a tariff if it was socially abnormal to do so. For example, they would not consider eating an evening meal at a late time because that is just not what is done. They would not do something if it did not meet social obligations or if they felt like they would become bad hosts or would disturb their neighbours. All those things were very complex social barriers to interacting with tariffs in order to change behaviour and were another really good reason we will not solve this at a large scale through individual behaviour change.