Despite the greatest price increases in years, affordability has hardly budged from six year peaks and in many of the nation’s most expensive markets, it’s still rising.

Year-over-year price increases through the final months of last year, which range from 4.5 percent/5.5 percent for the Case-Shiller composites to NAR’s 11.5 percent, have made less than a dent in soaring affordability ratings, especially in some of the nation’s most expensive markets in California and the Northeast.

The NAHB/ Wells Fargo Housing Opportunity Index has fallen only 4.3 percent from its January 2012 high. NAR’s Housing Affordability Index is down only 4.6 percent from its multi-year peak in January 2012. Both measures use median income levels, interest rates and home price data to calculate affordability on national and local levels.

However, in many markets, especially the nation’s most expensive housing markets, affordability is still rising. These include San Francisco, Boston, San Diego, Washington DC, Las Vegas, West Palm Beach, New York City, Orlando and Sacramento. In some, the pace of increase have slowed, but none have registered two consecutive quarters of affordability decline, as measured by Home Value Forecast’s Affordability Forecast, which uses regional household income trends with interest rates and local housing prices and to calculate the proportion of local households that can afford the median priced house.

Several leading foreclosure markets, where prices have increased the most over the past year, also witnessed a slight decline in affordability. These include Phoenix, Miami, Tucson, Santa Ana and Detroit.

A key factor in the disconnect between price and affordability trends are mortgage rates that remain historically low. “Mortgage rates started the year near record lows, which should continue to aid the ongoing housing recovery,” Frank Nothaft, Freddie Mac’s chief economist, said recently.

NAR’s Lawrence Yun recently predicted housing affordability would set a record in 2012, but rising prices would keep 2013 from being no better than the third best year since the index began in 1970. “Rising income and a gradual uptrend in mortgage interest rates will offset improvements in family income,” he said.

American markets are setting records for affordability around the world as well as at home. An international measure of housing affordability, the Demographia International Housing Affordability Survey, analyzed housing prices in 227 metro markets worldwide. Detroit topped the list for the most affordable housing market in the world. The U.S. had many of the most affordable markets that topped the housing affordability list. Other affordable markets included Atlanta, Cincinnati, Rochester, and St. Louis.

On the other end of the spectrum, Hong Kong remained the priciest housing market in the world. Other least affordable markets with a population over 1 million included: Vancouver; Sydney; San Jose, Calif.; San Francisco and London. In all, six major markets in the U.S. were rated as “severely unaffordable”: San Jose, San Francisco, San Diego, Los Angeles, and New York.