Does Spam Legislation Work?
Orin Kerr points to the following New York Times article (subscription required):
A spammer can often expect to receive anywhere from a 25 percent to a 50 percent commission on any sales of a product that result from a spam campaign, according to a calculus developed by Richi Jennings, an Internet security analyst with Ferris Research, a technology industry consulting firm.

Even if only 2,000 of 200 million recipients of a spam campaign - a single day's response rate for some spammers - actually go to a merchant's Web site to purchase a $50 bottle of an herbal supplement, a spammer working at a 25 percent commission will take in $25,000. If a spammer makes use of anonymous virus-enslaved computers to spread the campaign, expenses like bandwidth payments to Internet service providers are low - as is the likelihood of anyone's tracking down who pushed the "send" button.

We can create civil penalties or criminal penalties, but this will only open the way for spammers in countries with lax law enforcement (Russia) to dominate the market. It seems that there are only two ways of stopping this dynamic. One is to create liability on companies that advertise through spammers. The other is one that I remember reading a while back, to create a small tax on email (one tenth a penny an email) to have it delivered, significantly lowering the profit of companies that send out bulk email.

I am not sure what the problems of the first would be, but the second seems workable. Further, we could fine tune it so that it would not be so taxing on consumers. Instead of having the tax for each email, we could have it so that it is a tax for every UNSOLICITED email. You could import a version of your address book to your online carrier, and then every email that is received from one of those addresses would not bear the tax. Just a thought.