Apartment vacancy rates reached an average of 7.2 percent in the first quarter of 2009, a 1 percent increase over the previous two quarters and the highest level since 2004, according to real estate research firm Reis Inc.

At the same time, asking rents fell 0.6 percent and effective rents—what landlords are actually able to collect—declined 1.1 percent.

Metro areas where Reis says rents have fallen the most are:

• San Francisco, -2.8 percent
• New York, -2.6 percent
• San Jose, -2.5 percent
• Long Island, N.Y., -2.3 percent
• Fairfield County, Conn., -1.9 percent

Metro areas where rents have increased the most:

• Portland, Ore., 0.8 percent
• Miami, 0.7 percent
• Houston, 0.4 percent
• St. Louis, 0.4 percent
• Tampa-St.-Petersburg, Fla., 0.4 percent

Source: The Wall Street Journal, Nick Timiraos (04/2009)