Do do-gooders think they deserve more?

At the end of a productive working day do you feel you’re entitled to a treat?

In your mind, does a week of healthy eating cancel out a weekend bingeing on pizza and pinot grigio?

Scientists in the US have shown that the more virtuous we think we have been, the more we feel we've earned a blow-out.

Smug greens who install energy-saving products consume more. Owners of low energy washers do their laundry more often. And people leave energy-efficient light bulbs on longer than ordinary ones. Even people who are asked to imagine themselves committing a virtuous act are more likely to feel afterwards they deserved a pair of designer jeans. What's it all about?

Moral licensing, that's what. It's a challenge for sustainability advocates and a boon for luxury retailers. People who feel they’ve been ‘good’ will splash out without even thinking about where the urge came from. After all, it’s hard to argue with the part of your consciousness that says, “Go on, you deserve it.”

I must confess to wondering whether this means people who work in virtuous jobs, e.g. charities, get overwhelmed by moral licensing. Do they constantly feel, wow I’m so good I really must go out and treat myself (just as soon as I’ve finished organising the supply to fresh water to this third world village community)? I guess not, because surely faced daily with people who had nothing would dampen your enthusiasm for designer goods? . So what about other virtuous people? Priests? Nuns? Vegans? Are they secret shoppers? I’d love to know what you think about this.