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.

Mike B

My mom always taught me to simply not open the door for solicitors. Of course the best excuse that will diffuse ANY and ALL social pressure to give is to inform the person that you give through the mail.

Giving through the mail is often just plain smarter because many door to door charity solicitors are simply scam artists. If you ever give cash to a solicitor at your door you have to assume that the money is going right into their pocket.

So the mail excuse no only makes you not look like a scrooge, but also makes you look more savvy.

David Jones

The door-to-door issue can be confronted in a way that cold-calling cannot: a sign reading "Trespassers will be shot".


David, you have to watch out with those signs. They show intent. It's best never to announce that you intend to enforce the castle laws.


I've never understood why it's so hard for some people to just say "no." You'll never see that solicitor again. Are you really that desperate for a stranger's approval?


What is needed is a follow up (or a wrinkle in the study) to see if those who checked the Do Not Disturb box gave to a charity in another fashion.

The data may be explained by people just not wanting to meet someone at their door but yet are still charitable. Much more research is needed.

Sonja Coryat

Mainly I get religious fanatics coming to my door, at least one visit a week. I call them fanatics because who else but a religiously obsessed person would dare knock on my door and end up telling me that I will burn in hell unless I believe the way they do. How come they can go door-to-door all over the U.S. and get away with it? What if I went to their door and told them I wanted them to stop going to church. Would this be considered outrageous, or what? Of course it would. No non-believer would do that. Yet we continue to tolerate this offensive intrusion from religious fanatics. Why is this permitted, anyway.


#2 - no one will seriously consider a sign that says "Tresspassers will be shot", in that the costs to you to shoot someone are extremely high (prison time), unless the trespasser is an immediate danger to you or your family. Only a very few states give you much leeway in this.


Put another way, this is a measure of social cowardice.

I decided long ago that if I were going to decline to give money to a homeless beggar, for instance, I should have the spine to look him in the eyes and say, "no." It still makes me uncomfortable, and I still insist on making eye contact. The weird social "norm" of pretending these people are invisible is weak in terms of honour and personal dignity. I give money occasionally, decline frequently, but at least the beggar and I have a human interaction in the process.

The same thing applies to a charity, though there the risk of an invisible class is smaller. But there is something repulsive about the "savvy" solution of Mike B (hiding and lying), above, that reflects a lot of what is wrong with our society.



This isn't about altruism. This is about how little it takes to annoy your average American bear.

Cheryl G.

I don't consider this form of altruism to be nearly as reflective (although it would be a quick test) as anonymous polling to see who would give something up to make things better for a community. Examples: lessening the sound of church bells if they were too loud for the closest neighbors; driving slower through residential streets; taking a dog out on a leash in the evening/morning so that it didn't bark long enough to wake the neighbors, etc.


I used to work for a public interest group on environmental campaigns. Through constant door-to-door canvassing, I found that the homeowner was much more likely to give a donation if I gave them no option to give any other way (such as through the mail). When I did give that option, even excited and interested people hardly ever sent anything in.

It was odd doing this kind of work however, because I knew that if somone came to my door I would be incredibly sceptical as well. I felt incredibly awkward almost demanding that I at least say my piece before they close the door on me. But the social pressure worked. Once they heard what I was about, combined with the fact that I was standing face to face with them, as opposed to an impersonal, electronic manifestation of a human being (aka: the phone), they listened; some of them even donated. This was a successful tactic, and I raised over $10k for our campaign in the span of just one summer.

I didn't like the work that I did. But do I think I helped to bring about positive change? Absolutely. Would I give to someone at my door doing the same thing I did? I don't know. It was an incredibly conflicting experience, but one I don't regret.


Bill Allen

There already is such a thing. It's called the "no solicitors" sign.

Steve Crisp

"The door-to-door issue can be confronted in a way that cold-calling cannot: a sign reading "Trespassers will be shot"."

And those who survive will be buried alive.


I don't open my door to strangers. If the person is not expected (or a friend, neighbor or a workman with an appointment for instance), I ignore them. I can see who is there. If they persist I simply shout through the door "Please go away." My time is valuable to me and just because you can knock on my door does not mean I have to open it (same for phone calls). I have NO GUILT about this. My charitable habits are NOYB by the way.

I used to get mad about knockers and unsolicited phone calls. Now I ask callers for their home phone number and what time they will be watching their favorite TV show or eating dinner so I can call them back then. Now they get mad and I laugh.


My take is a tad different. I live in a smaller community so that the solicitors are for the Boy Scouts or the local schools. Therefore we know these people or they actually could be our kids. I therefore have an envelope of cash (not a wad) that I can use to buy their overpriced items. I don't have to search for the dough and consider it a part of being a good neighbor. Granted if I lived in NYCity where apparently everyone is anonymous I would feel much different.

Dan Johnson

The research presumes that giving at the door is "altruistic" - I believe that this is a very narrow metaphor for altruism, which the author has not validated.


I never give to door-to-door solicitors. It's too hard to figure out if they are legitimate.

I tell all solicitors I give online or by mail after I do research and invite them to leave minimal info. One local environmental org does an annual door-to-door push and they won't stop their pitch even when I do that. I used to give to them. Now I don't. I tell them why every year.


What's funniest about the premise for the experiment and some of the reactions here is the notion that giving money is altruistic. That's a very capitalistic approach to charity.

Giving money is a way to help people but extremely passive. Purchased peace is fine but consider that some of us have dedicated our lives to working for others and, as a result, do not make money we can give away to strangers who come knocking on the door with an issue.

Why isn't there any social pressure on Americans to do things for society, rather than just contributing to organizations to do things (organizations that will spend much of the collected money on collecting more money through events, dinners, entertainments for the rich in the hope they will give even more than the poor sod who opened his door)?


With all the crime one hears about in the news, it's not safe any more either for residents or for the people going door to door.
We don't answer our door any more unless we're expecting friends, good neighbors, or family, or a repair service we have called. There's no way of knowing if people at the door really are who they say they are, or if they truly represent a legitimate charity. They could be scam artists or even dangerous criminals.
It's not safe either to send one's children door to door for school fundraisers, etc., unless you know who lives in the houses in the community, and know that they are reliable and interested in supporting the fundraiser. One can always just give a donation to the fundraiser instead of buying the wrapping paper, candy, or whatever product is being sold to raise money for the project.


I have had FIOS (armed with personal info on me and my family), religious zealots, and girl scouts come to my door. I will give to the neighborhood kids interests but uniformly not to anyone else.

I tell them I gave at the office and I'd rather burn in hell than change my religion.