In addition, the still high unemployment rate and overall global economic uncertainty outweighs the allure of more affordable homes. In the end, while affordability should help boost demand in the housing market, tight credit conditions should limit loan qualification and thus restrain some of the impact from affordability. New-home sales (which normally surge after a recession) are bucking their historical trend. This is in fact the first time over the past 42 years that new-home sales failed to surge in the aftermath of the recession. Instead, this time around, sales have fallen 15%-20%, with new-home sales currently trailing the 40-year average by 55%, driven by foreclosures, tighter credit conditions and quite possibly by rising construction costs. The residential construction producer price index, for instance, rose 5.5% year over year, up nearly 17% since early 2007. This contrasts widely with the 3.4% year-over-year decline in the value of home prices (measured by the S&P/Case-Shiller index), suggesting that the costs of building have outweighed the costs of selling, putting additional strain on industry profit margins. What's more, revenue from homebuilders has declined nearly 90% since the peak in 2006 (although margins, while volatile, have improved somewhat since 2009). Arguably, the most significant factor driving home prices is the pace of foreclosures. Foreclosures influence home values as the change in delinquency rate impacts existing home inventories. So while delinquencies as a percent of total loans have declined to 7.9% in the third quarter from nearly 10% in March of 2010, foreclosures still remain at near-record levels of 4.3% of total loans. According to Realtytrac new foreclosure activity in November 2011 was 224,000, just shy of the 239,000 pace seen throughout 2011, suggesting that the pace of foreclosure activity still remains troubling. Consequently, the existing stock of housing inventory is likely to remain elevated, indicating that home prices may remain subdued. The current stock of total housing inventory (existing plus new) is currently 2.7 million units. Although this has steadily improved from the nearly 5 million units on the market in 2007, the existing supply still translates into 7 months worth of inventory, at current sales rate. This is also a few hundred thousand units higher than the average seen over the past 30 years. Similarly, estimates of the shadow inventory (foreclosures plus 90-day delinquent home that may be added to the existing stock of inventories) indicate the potential to see the current total inventory double, resulting in nearly a 20-month supply of homes (Chart 4).