• Loren McDonald asks if e-mail marketers are sending too many messages and offers some ways you can tell if you’re over-sending.
• Target Analytics has released its 2011 index of non-profit fundrasing performance, based on 83 organizations. Roger Craver wants to know what these organizations’ direct marketers are doing wrong.
• You thought America had a real estate bubble? China’s central planners have built whole cities that now lie empty. Via Tim Cavanaugh.
• Dan Mitchell passes on a slightly bawdy joke about unions.
• Last but not least, Pierre LeBrun argues that Alex Ovechkin’s diminished numbers this year reflect a player newly committed to team victory over personal success. The Capitals, perhaps not coincidentally, have clinched the Southeast division for the fourth straight year.

Like many urban problems, the decline of walkable, livable urban centers can be traced to government intervention. In *Triumph of the City, *Ed Glaeser argues that restrictive zoning regulations served only to distort markets, artificially limit density and make dense areas unaffordable.

In a new article for Cato Ubound, Donald Shoup argues that minimum parking requirements—which require developers to build a certain number of off-street parking spaces—have promoted auto-oriented urban design over denser, more walkable forms:

First, parking requirements prevent infill redevelopment on small lots, where fitting both a new building and the required parking is difficult and expensive. Second, parking requirements prevent new uses for many older buildings that lack the parking spaces required for the new uses…

Removing a parking requirement is not the same, however, as restricting parking or putting the city on a parking diet. Rather, parking requirements force-feed the city with parking spaces, and removing a parking requirement simply stops the force-feeding. Ceasing to require off-street parking gives businesses the freedom to provide as much or as little parking as they like. Cities can remove minimum requirements without imposing maximum limits, and opposition to parking limits should not be confused with support for minimum requirements. Minimum parking requirements may be our most disastrous experiment ever in social engineering, and ceasing to require off-street parking is not social engineering.

Over at Market Urbanism, Stephen Smith points to a study on how parking minimums distort builders’ decisions. The study, Smith says, finds “that at least half of all non-commercial properties have more parking than they would otherwise choose, and that the excess can oftentimes be quite large.”

• Rep. Paul Ryan makes the case for his 2012 budget. My colleagues at Heritage give it two cheers, and Ross Douthat calls it the “triumph of policy” over politics.
• E.J. Dionne warns that Ryan’s budget would mark the end of progressive government, which is actually a good thing.
• A new report released by the New Organizing Institute both offers insights into e-mail advocacy and explains why careful testing is important.
• Megan McArdle explains that the complexity of accounting practices means  it’s perhaps futile to try to design a corporate tax without “loopholes” of any sort. “A corporate income tax,” she writes, “needs to start by calculating income, and as anyone who has ever looked at a corporate financial statement knows, that’s really complicated.”
• Mark Hemingway points out the facts about who has received campaign donations post–Citizens United. We shouldn’t forget, though, that principle is a better way to make policy than a cui bono analysis.
• Last but not least, Trent Hamm makes the case that your leisure time should not be spent idly. Leisure time, he writes, “can provide all the space you need to take on personal goals and get involved in things you might not otherwise enjoy.”

• How a cab medallion system is counterproductive: it introduces artificial scarcity and distorts drivers’ incentives.
• Russ Roberts points out that Japan’s fuel shortages are no mystery and that the solution isn’t more regulation. Shortages are a result of price controls that keep a scare product artificially inexpensive.
• Some fancy CSS work by Josh Brewer yields an impressive typographic result.
• New York City’s parking “privatization” scheme is a bad idea that isn’t really privatization at all, Stephen Smith argues.
• Last but not least, Dan Mitchell rounds up the late-night hosts’ cracks about Libya. My favorite, from Conan: “It’s being reported that Moammar Gadhafi is surrounded by an élite core of female bodyguards. In a related story, Charlie Sheen invaded Libya.”

One way bloggers can earn incremental income is through affiliate marketing programs, among which Amazon’s is perhaps the most popular. Bloggers simply link to Amazon products, adding a special referral code, and they are given credit for the sales they generate.

Generating these tracking codes can be something of a pain. Amazon’s own utility is clumsy and offers up a long, clunky URL. Ragaskar’s WordPress plugin aims to fill the void by automatically appending tracking codes to Amazon links in posts, but this can still generate clunky links.

Based on Ragaskar’s plugin, I whipped up the following code:

    add_filter('the_content','filter_amazon_associate_filter');

    add_filter('comment_text','filter_amazon_associate_filter');

    

    function filter_amazon_associate_filter($content) {

        $affiliate_code="YOURCODEHERE";

    

        $content=preg_replace(

            '/http:\/\/[^>]*?amazon.([^\/]*)\/([^>]*?ASIN|gp\/product|exec\/obidos\/tg\/detail\/-|[^>]*?dp)\/([0-9a-zA-Z]{10})[a-zA-Z0-9#\/\*\-\?\&\%\=\,\._;]*/i',

            'http://www.amazon.$1/exec/obidos/ASIN/$3/'.$affiliate_code,

            $content

        );

        return $content;

    }

Very simply, this code scans through your posts and comments and replaces ugly Amazon links with somthing like http://www.amazon.com/exec/obidos/ASIN/B0048EJXCK/nathward-20.

To add this to your site, simply place the above code in your WordPress template’s functions.php file and replace YOURCODEHERE with your Amazon affiliate code.