For many Americans, deciding whether to buy a house or to rent is one of the most significant economic decisions they will make. For that reason, the buy versus rent debate provides an excellent case study for Econ teachers and students. David Leonhardt has spent a lot of ink on the subject for the New York Times over the last several years--he calls it a "near-annual habit". He writes an update about the rent-vs-buy dilemma in today's Times, and the most basic way to look at the numbers suggests that if one is planning on living in a home for five years or more, buying makes sense. But then one has to consider the specific market. Leonhardt: Within this basic framework, the numbers — specifically, something called rent ratios — are the next place to turn. A rent ratio is the sale price of a house divided by the annual cost of renting an equivalent house. When the ratio is below 15, most people should lean toward buying. To see why, look at the Atlanta area, where the average ratio is now about 13. Combined with today’s low interest rates, that ratio means that the typical monthly mortgage payment is several hundred dollars lower than the rent on an equivalent house. Over time, this difference helps make up for the other costs of owning, like closing costs and borrowing costs. And, yes, a mortgage costs money, despite the tax deduction. Only if home prices in Atlanta fall further and don’t recover for years would most buyers today have reason for regret. The other areas where the average ratio is below 15, according to Moody’s Analytics, include Los Angeles, Miami, Minneapolis, St. Louis, Las Vegas, Cleveland, Detroit, Phoenix, Pittsburgh and Tampa, Fla. Read Rent or Buy, a Matter of Lifestyle here . And take a look at the this multimedia tool at the New York Times website. It allows you to enter specific home costs and rental costs to determine which option is better: Click here to use the multimedia tool .