Thinking about the Opower study (Alcott, 2011) and similar social norms-based nudges to increase energy conservation behaviour, I wonder if it would be even more effective to personalise the descriptive norm information further by taking into account the heterogeneity of home sizes and households.

For instance, a particular neighbourhood might be a mix of 3 and 4 bedroom houses as well as apartments and smaller houses. Messaging based on the average energy usage of everyone in that neighbourhood might not be particularly effective if you have either a much smaller or larger-than-average house or household. Of course, it might not be feasible to target individual households with information about the average usage of only neighbours who have similar households (e.g. small apartment, no kids), but perhaps listing the average usage for a number of different household types would allow people to feel more personally engaged with the messaging.

An example person living in a large house with a large family might dismiss the average energy usage statistics as not applying to them and not feel motivated to change their energy usage, thinking "Of course my energy usage is above average, that's just how much I need". A message saying “the average monthly energy usage of neighbours living in a 4-bedroom house is X, and the average usage of neighbours living in a 2-bedroom apartment is Y” might help people feel the norm applies to them even more. If you did have information about individual households, you would be able to send out more accurate injunctive messages as well.

Does anyone have any thoughts on this? Would it be considered invasive to say “Compared to other neighbours with homes of a similar size to yours with X number of inhabitants, your energy savings are above average”? Maybe it would be better not to mention household size, especially since energy providers might not have that information anyway? Do you know if it’s already been done?