I was showing off in the Haddon Library to a student the other day, and I'm afraid I told him this story. Remind me not to tell it again now it's online.
In March 1986, I was Assistant Librarian at the Haddon, and the other two members of the library staff were both on long-term sick-leave. Working with me were two part-timers.
The end of the Lent Term approached, and with it the end-of-term recall of loans. In those pre-automation days that meant a ridge of activity, daunting even when the Haddon was fully staffed. A wiser person would have looked at the task and the resources, and concluded that it would be a good idea to give the end-of-term recall a miss for once. But in those days I was bolder than I am now, and saw in the situation an opportunity to try something.
I had read of someone who had conducted research into research. He had recruited a number of researchers to act as his subjects, and divided them into two groups. Both groups were asked to report to him regularly on the progress of their own research, but one group was asked additionally to write cheques to organisations of whose aims they disapproved, and leave these cheques with him. If research by the writers of the cheques did not prove verifiably fruitful, the cheques would be forwarded to the organisations concerned. At the end of the experiment, members of the group that wrote the cheques were found to have made better progress than members of the control group, who faced no such financial loss. (In 2011, I tried and failed to track that story down; let me know if you have any leads.)
My exploit did not involve a controlled experiment, or any money but mine. What I did was to circulate to Haddon users, a fortnight or so before the end of term, a notice whose wording I remember as follows:
THREE GOOD REASONS FOR RETURNING YOUR LOANS HERE BY TUESDAY MARCH 11
1. You will not be allowed to borrow any books for the vacation until your loans for the term are back.
2. We are extremely hard-pressed at the moment, with three people's work being done by one and two halves. The fewer overdues we have to send, the better.
3. I intend to donate 1p to Conservative Party funds for every overdue note we send out on Wednesday March 12. Please help me to keep this sum as small as possible by returning your loans on time.
I cannot say whether it worked in terms of persuading people to return their books. The donation I ended up sending to Conservative Central Office came to 86 pence, but, lacking figures for overdues sent at the end of other terms, I had no means of making a comparison.
The biggest flaw in this incentive was its unexamined assumption about the political bias of the Haddon's users. But the student who said, a few weeks later, that he'd kept books back in order to boost the donation made this claim in a funny voice. Was he joking? Irony is the blind spot in my sense of humour.
A kind friend asked if I'd mind him sharing the story with the Times Diary. They rang me to check it. Afterwards I had a major backlash from the left wing of my conscience for talking to Murdoch's paper, and did penance with soap in my mouth for three quarters of an hour.
None of this is the kind of thing I do now.