Homebuyer affordability remains near an all-time high, so where are all the first-time homebuyers? According to indexes that incorporate gross measures of house prices, interest rates, and household incomes, affordability remains at unprecedented levels. The National Association of Realtors® index, for instance, shows that the median-income household can afford to buy a home in all but 7 percent of the largest metros. Given that affordability looks good on paper, the lack of first-time homebuyers in all metros has been surprising. In 2013, first-time homebuyers made up 38 percent of home purchases, below the historical average of 40 percent, dating back to 1981. The most recent American Housing Survey shows that 3.3 million households were first-time buyers in 2009-2011, a 22 percent drop from the 2001 survey, which covered 1999-2001. This decline in first-time buyers comes in spite of real mortgage payments for the median home that remain below $800 (levels unprecedented before the recession) and a 7 percentage point decline in the mortgage payment-to-income ratio since 2001.
via Housing Perspectives (from the Harvard Joint Center for Housing Studies).
On major facor that the indexes cited in the article that refer to affordability neglect to consider is the significant amount of student loan debt that so many would be first time home buyers are saddled with.