There are a lot of tax-delinquent properties in Philadelphia, and the city is preparing to equip itself with the power to foreclose on deadbeat property owners. That should raise money by encouraging people to pay their taxes, and when people don't pay, the city can raise funds by selling the properties off. And yet Jonathan Geeting writes that some people are concerned about this strategy: "Speculators could form shell companies to buy up land from the land bank and then just sit on it, preventing timely development of more productive uses." That still doesn't sound as bad as tax delinquency to me, but as Geeting argues, this is exactly the kind of situation where taxing land rather than buildings makes a big difference. Evan Soltas also recently did a good post on the case for taxing land.