The spam solution

You want to get inside my e-mail inbox? Then pay me
September 19, 2003

Like many people, I have passed a threshold in the last year or so. Spam has gone from one of life's little nuisances to a threat to the usefulness of e-mail. Technologically, no quick fix is in sight. But it is helpful to think about what sort of fix we should be hunting for. The answer, I think, is this: I should have property rights to my e-mail inbox, and I should be able to charge you for admission.

The spam problem is a new instance of a very old dilemma: what economists call the tragedy of the commons. When any resource is both valuable and freely available, people will tend to overuse it. Moreover, everyone anticipates that everyone else will overuse it, so everyone tries all the harder to get in while the going is good. The tragedy is that everyone's least-favoured outcome-the depletion or exhaustion of the resource-is assured.

Centuries of theory and practice have thrown up two effective remedies. One is to appoint a conservator with the power to mete out the resource: say, the US fish and wildlife service. The other is to create property rights to the resource and allow a market to develop. What people own, they conserve.

In the case of e-mail, the valuable resource at issue is my attention, and the problem is that access to it is free. People who really want to talk to me need to make no more effort than people who want to waste my time. My inbox is less like a mailbox and more like a dumping ground, through which I must sift to find items of interest.

Some people have proposed that the market-based solution to spam is to levy a public fee or tax for sending e-mail. In effect, the government would become postmaster general of cyberspace. But webheads are understandably reluctant to make the government the conservator of e-mail. Government oversight could open the internet to all kinds of regulation and tempt politicians to milk it for revenues. A bigger objection is that the government is notoriously bad at setting prices. Just imagine the equivalent of a postal rate commission for e-mail. No one-size-fits-all price could possibly be right, because we all place a different value on our attention. Some people even like spam.

Suppose instead that we gave me legally enforceable conservatorship of my mailbox. Then I could sue you for trespassing if you sent e-mails after I told you to stay out. This is not as farfetched as it may sound: courts and legal scholars are already developing a concept of "cybertrespass." Suing, however, would be a massively inefficient remedy of last resort. As for the remedy of first resort, I would charge you. Are you a stranger who wants to get into my e-mail inbox? Pay me.

But isn't the great benefit of e-mail that it's free? Not exactly: spam filters, clogged mailboxes and server overload are existing-and rising-costs for using e-mail. The problem is that the wrong people are paying for it.

The solution is to make spammers pay their targets, instead of forcing the targets to pay for spam. Everyone could charge a different entrance fee for access to his or her inbox. If I like hearing about cheap Viagra, I could charge nothing or almost nothing. The higher my price per e-mail, the less spam I would receive-and a larger portion of the spam that I did get would be targeted, rather than random, so it might actually be interesting. If I set a very high price, I would receive no spam at all. By experimenting, I could find a price that suited me, and I could always adjust it to suit my needs. Friends and "whitelisted" designees wouldn't have to pay at all.

The system could be self-financing. Some portion of what I charge per incoming e-mail could be siphoned off to pay administrative costs. Furthermore, most people, and probably even most reputable companies, send and receive e-mail in roughly equal quantities. So, after administrative expenses, the costs would net out-except for people who do a lot of sending but not much receiving, namely spammers.

I vetted this idea with a number of cyber-law specialists, and they raised some thorny technical issues, such as who would pay for e-mail bounces. There is also the question of how to conduct billions of transactions without gumming up the system. One possible answer is proposed by the economist David Friedman: reusable cyber-stamps. When I receive e-mail, I would collect the required cyber-postage-assuming, of course, you had attached enough. Unlike conventional stamps, however, these would be reusable. I would turn around and send them out again with my own e-mail.

The pay-me approach is a variant of the so-called "digital handshake," in which unsolicited e-mail is intercepted with a request for a specific response. Only if the right answer is given is the mail delivered. The pay-me approach essentially replaces the question, "Who are you to deserve my attention?" with "How much will you pay for my attention?" My software could be programmed to ask strangers for, say, one cent. Yours could be programmed to offer a maximum of half a cent, or five cents. If my demand was under your limit, you would pay and your mail would be delivered. If not, no deal.

If all that sounds hairy, remember that the US financial system settles hundreds of millions of transactions worth something like $3 trillion-more than a quarter of the annual GDP-every day, and no one thinks a thing of it. Remember, also, that today's system is anything but free and the costs are going up. So if you want to e-mail me, pay up.