No comment(s)

In July, just before travelling, I closed the comments on this blog, not because I don't appreciate smart topical comments, but because every morning I had to delete spammy comments on old posts by people purporting to buy kidneys.

Here are those from the last day I allowed comments

	We are urgently in need of kidney donors in wockhardt hospital India for the sum of $500,000,00,( 3 CRORE INDIA RUPEES) All donors are to reply via Email: wockhardthospital7@gmail.com on The Econometrics of Matching Models by Pierre-André Chiappori and Bernard Salanié in the JEL	wockhardt hospital	on 7/12/18
	We are urgently in need of kidney donors in wockhardt hospital India for the sum of $500,000,00,( 3 CRORE INDIA RUPEES) All donors are to reply via Email: wockhardthospital7@gmail.com on Organ donation rates in Canada	wockhardt hospital	on 7/12/18
	We are urgently in need of kidney donors in wockhardt hospital India for the sum of $500,000,00,( 3 CRORE INDIA RUPEES) All donors are to reply via Email: wockhardthospital7@gmail.com on Raj Chetty at the LSE: How Can We Improve Economic Opportunities for Low-Income Children?	wockhardt hospital	on 7/12/18
	We are urgently in need of kidney donors in wockhardt hospital India for the sum of $500,000,00,( 3 CRORE INDIA RUPEES) All donors are to reply via Email: wockhardthospital7@gmail.com on More on kidney black markets in India	wockhardt hospital	on 7/12/18
	We are urgently in need of kidney donors in global hospitals group India for the sum of $500,000,00,( 3 CRORE INDIA RUPEES) All donors are to reply via Email: onlinecareunit@gmail.com on 77 Kidney Exchange transplants in 2015 at one transplant center in India	Global Hospitals Group	on 7/12/18
	We are urgently in need of kidney donors in global hospitals group India for the sum of $500,000,00,( 3 CRORE INDIA RUPEES) All donors are to reply via Email: onlinecareunit@gmail.com on Ten kidney exchange transplants on World Kidney Day in Ahmedabad, India Delete | Not spam	Global Hospitals Group	on 7/12/18

The Economics of Spam by Rao and Reiley

In the latest Journal of Economic Perspectives: The Economics of Spam (open access).

Justin M. Rao and David H. Reiley

"We estimate that American firms and consumers experience costs of almost $20 billion annually due to spam. Our figure is more conservative than the $50 billion figure often cited by other authors, and we also note that the figure would be much higher if it were not for private investment in anti-spam technology by firms, which we detail further on. Based on the work of crafty computer scientists who have infiltrated and monitored spammers' activity, we estimate that spammers and spam-advertised merchants collect gross worldwide revenues on the order of $200 million per year. Thus, the "externality ratio" of external costs to internal benefits for spam is around 100:1. In this paper, we start by describing the history of the market for spam, highlighting the strategic cat-and-mouse game between spammers and email providers. We discuss how th e market structure for spamming has evolved from a diffuse network of independent spammers running their own online stores to a highly specialized industry featuring a well-organized network of merchants, spam distributors (botnets), and spammers (or "advertisers"). We then put the spam market's externality ratio of 100 into context by comparing it to other activities with negative externalities. Lastly, we evaluate various policy proposals designed to solve the spam problem, cautioning that these proposals may err in assuming away the spammers' ability to adapt."

Spam newspaper

One of the odder features of the internet ad economy is that it is apparently profitable to create internet sites that draw some search traffic, without having any real theme or original content. I'm speculating that CamKh.com is such a site, since it is regularly reposting my blog posts, without however linking to this blog. (In fact, my posts seem to make up a large part of the non-ad content of their Technology section) The site has a vaguely Cambodian theme, but obviously doesn't feel obliged to stick to that.

So, if you happen to be reading this on CamKh.com, the link to my actual blog is here: Market Design.

Update: and (recursively), here is this post, uploaded automatically on the spam newspaper itself.

Craigslist and spam

Wired has a long article about Craigslist and its founder; the tone is simultaneously admiring and baffled: Why Craigslist Is Such a Mess. It's well worth reading.

Here's one paragraph that stood out:
"The battle flows back and forth. Captchas—distorted words that can be interpreted by humans more easily than by machines—tamed spam on craigslist for a while. Then it came back full force, not because the spammers had solved the difficult problem in artificial intelligence but because they had hacked an easier problem in global economics. I recently established a friendly email dialog with a young man in Dhaka, Bangladesh, who works on a 13-person team that creates craigslist spam. He fills in Captchas, creates new accounts with masked IP addresses, and posts ads all day long using text from a database provided by his employer, an anonymous spam king. The going price for a spam post on craigslist is about 50 cents, with large discounts for volume. When I told Buckmaster about my new friend, he took the news calmly. "These are technically sophisticated people who take pride in their work, and when we knock them down they don't just decide to go find something else to do. You could say we are breeding the perfect spammer." "

Automated spam blog detection

Woke up this morning to find this on my blog dashboard:

"This blog has been locked due to possible Blogger Terms of Service violations. You may not publish new posts until your blog is reviewed and unlocked.
This blog will be deleted within 20 days unless you request a review."

And this in my email:
"Your blog at: http://marketdesigner.blogspot.com/ has been identified as a potential spam blog. To correct this, please request a review by filling out the form at http://www.blogger.com/unlock-blog.g?lockedBlogID=4748060798655400108

Your blog will be deleted in 20 days if it isn't reviewed, and your readers will see a warning page during this time. After we receive your request, we'll review your blog and unlock it within two business days. Once we have reviewed and determined your blog is not spam, the blog will be unlocked and the message in your Blogger dashboard will no longer be displayed. If this blog doesn't belong to you, you don't have to do anything, and any other blogs you may have won't be affected.

We find spam by using an automated classifier. Automatic spam detection is inherently fuzzy, and occasionally a blog like yours is flagged incorrectly. We sincerely apologize for this error. By using this kind of system, however, we can dedicate more storage, bandwidth, and engineering resources to bloggers like you instead of to spammers. For more information, please see Blogger Help: http://help.blogger.com/bin/answer.py?answer=42577

Thank you for your understanding and for your help with our spam-fighting efforts.

Sincerely,

The Blogger Team"

Let's see if I can publish this. (Update: it looks like I can still publish, but have to interpret a captcha to show I'm probably human...)

Further update: how could Google's automatic spam blog detector be improved? Well, Google offers a lot of tools for reading blogs. Some fraction of my regular readers apparently read Market Design on Google Reader, since it reports 858 subscribers when I checked just now. (You can check too, or subscribe, by going to Google Reader and typing "market design" after clicking on the + box next to "add a subscription." You aren't committed at that point, but you can see the feed, and the number...)

So, a thought for the humans who program the automatic spam detector: check if spam blogs have fewer subscribers than real blogs, and, if so, include that in the next version of the algorithm.