Homes may be cheaper, but they are not more affordable

The National Association of Realtors' Housing Affordability Index is about 53 points higher now, at 171.6, than it was in 2006, at 107.6.

But does that mean homes are more-affordable now for Americans than they were three years ago? The answer is, "that depends." Here's why:

Two factors are working in favor of prospective homeowners. First, the U.S. median home price, at $172,900 as of May, is about 22 percent lower today than the $221,900 average price level for 2006. That's a trend that's helping prospective buyers.