How are those resolutions going? Still going to the gym? If not, you’re not alone.

Let’s think about incentives. If some benevolent patron had paid you a modest sum — a few pounds a day, perhaps — for keeping your resolution throughout January, would that have helped you keep fit now that January is behind us?

The answer is far from clear. An optimistic view is that by paying you to look after yourself in January, your mysterious patron would have encouraged you to form good habits for the rest of the year. The most obvious case would be if you were trying to give up cigarettes; paying you to get through the worst of the withdrawal period might help a lot. Perhaps diet and exercise would be similarly habit-forming.