O'ahu single-family home values this year may be faring a bit better than local home resale data suggest, according to a new federal report.

The Federal Housing Finance Agency yesterday reported that single-family home values in the first quarter declined 4.7 percent on O'ahu compared with the same quarter a year earlier.

That compares with Honolulu Board of Realtors data indicating the median price of homes sold in the first quarter was down 8.1 percent to $570,000 from $620,000 in the 2008 first quarter.

The federal report is based on sale or refinancing values of homes during the quarter compared to sale or refinancing values for the same properties a year earlier.

Because of the same-home methodology, the federal data represent relatively few transactions, but are considered by some industry followers to represent inherent property values better than median sale prices.

A median price is a point at which half the sales are for more and half for less. Median prices are influenced by differences in the mix of homes — such as a greater preponderance of older and smaller homes or newer and bigger homes.

The mix factor, which can be magnified when the number of sales is relatively small, is one reason why some discount the usefulness of median resale figures.

According to the Federal Housing Finance report, O'ahu home values declined 1.1 percent from the fourth quarter to the first quarter. By comparison, the median price for sales of all previously owned single-family homes in the same period was down 6.6 percent.

One constraint in the federal report is that it's limited to homes bought with conforming mortgages purchased or backed by Fannie Mae or Freddie Mac, which excludes a significant part of the market financed by subprime and jumbo loans.

Federal Housing Finance is the successor agency to the Office of Federal Housing Enterprise Oversight, and is responsible for regulating the two mortgage finance giants taken over by the federal government last year.

Out of 294 metropolitan areas, Honolulu, or O'ahu, ranked 201st with its 4.7 percent year-over-year decrease, meaning 200 other areas fared better.

Part of the reason is many markets have already suffered severe downturns and are now rebounding, whereas O'ahu has only seen a modest decline that began last year.

Of the 294 metro areas, 88 had home value gains. The strongest market was Corpus Christi, Texas, with a 4.1 percent increase. The worst market was Merced, Calif., with a 37.8 percent decline.

The agency also reported home values by state based on same-home purchases but not refinancing. The figure for Hawai'i was down 4.3 percent in the first quarter compared with a year earlier, and down 5.4 percent from the fourth quarter to the first quarter.

Nationally, the agency reported that same-home sale prices declined 7.1 percent in the first quarter from the same quarter a year earlier, and declined 0.6 percent from the fourth quarter to the first quarter.

In the year-over-year comparison, 28 states had better home value changes than Hawai'i. Alaska was ranked first with a 4.8 percent gain. The worst state was Nevada with a 31.1 percent decrease.