What's Next: A Do-Not-Knock Registry?

John List, one of the heroes of SuperFreakonomics, is a master of clever field experiments concerning fairness and altruism. He is particularly adept at imbuing experiments, whether in the field or the lab, with real-world wrinkles that make the results more believable.
He has already done some noteworthy work on door-to-door charitable solicitations. Now he’s written a new working paper (pdf here; abstract here) along with Stefano DellaVigna and Ulrike Malmendier (we’ve featured their work before as well), whose real-world wrinkle is as clever as it gets: distributing a flyer that tells a potential donor the date and time that a solicitor will be visiting, thereby giving donors the opportunity to be out of the house or simply to not answer the door. This enables the researchers to measure the degree to which altruism is affected by social pressure (to say nothing of tax breaks).
So what happens?
As List, DellaVigna, and Malmendier write:

We find that the flyer reduces the share of households opening the door by 10 to 25 percent and, if the flyer allows checking a “Do Not Disturb” box, reduces giving by 30 percent. The latter decrease is concentrated among donations smaller than $10. These findings suggest that social pressure is an important determinant of door-to-door giving. Combining data from this and a complementary field experiment, we structurally estimate the model. The estimated social pressure cost of saying no to a solicitor is $3.5 for an in-state charity and $1.4 for an out-of-state charity. Our welfare calculations suggest that our door-to-door fund-raising campaigns on average lower utility of the potential donors.

John List had better be careful. His research is very valuable to the philanthropic community; but if this latest paper engenders a public outcry for a “do-not-knock” registry, he might quickly become a pariah.