The federal housing tax credit expires in just over a month, but buyers seem to be staying away from new homes.

According to data released Wednesday by the U.S. Census Bureau, sales of new homes fell to a seasonally adjusted level of 308,000 in February, which represents a new record low for the indicator.

On a comparison basis, this translates into a monthly decline of 2.2% and a year-over-year drop of 13%.

Such a performance troubles economists. “Usually, one can shrug off a disappointing new home sales reading since the top line estimate, which is based on a small sample, is almost never statistically significant. February's number, however, cannot be dismissed because it is highly statistically significant,” said Patrick Newport, U.S. economist at IHS Global Insight. “The fact that sales have dropped four straight months is also significant since, according to the press release's explanatory notes, ‘It takes four months to establish a trend for new homes sold.’”

Data released earlier this week also showed that sales of existing homes have also declined for three months in a row.

With sales of new homes slowing, inventories have begun to rise. In February, builders had 236,000 homes for sale, which represents 9.2 months of supply at current sales rates.

But if sales don’t pick up, builders may have more than that on their books. “Over the past four months, new home sales have dropped 23% while single-family permits have risen 14%,” Newport noted. “This is perplexing, since these two numbers usually track one another closely. The divergence suggests that builders, anticipating a surge in demand from the second home buyers' tax credit, took out permits to meet a demand surge that has yet to materialize.”

The release contained one nugget of good news: the median price for a new home rose 6.1% in February, to $220,500.

Alison Rice is senior editor, online, at BUILDER magazine.