This fascinating article form the NYT (Utilities turn their customers green, with envy) discusses how the Sacramento Municipal Utility has had great success in achieving their energy-reduction targets by informing their customers on how their energy usage stacks up against that of their neighbours.

Last April, it began sending out statements to 35,000 randomly selected customers, rating them on their energy use compared with that of neighbors in 100 homes of similar size that used the same heating fuel. The customers were also compared with the 20 neighbors who were especially efficient in saving energy.

Customers who scored high earned two smiley faces on their statements. “Good” conservation got a single smiley face. Customers like Mr. Dyer, whose energy use put him in the “below average” category, got frowns, but the utility stopped using them after a few customers got upset.

When the Sacramento utility conducted its first assessment of the program after six months, it found that customers who received the personalized report reduced energy use by 2 percent more than those who got standard statements - an improvement that Alexandra Crawford, a spokeswoman for the utility, said was very encouraging.

I love this both because it’s simple and it works, and also because it’s a great example of how transparency and information design can contribute to social progress.