Construction input prices decreased by 0.2% for the month of December, according to a new Associated Builders and Contractors (ABC) analysis of U.S. Bureau of Labor Statistics Producer Price Index data. Nonresidential construction input prices decreased 0.2% for the month, and overall construction input prices are 0.9% higher than a year ago.Decembers nonresidential construction input prices are now also 0.6% higher. Prices for steel mill products (-3.0%) and iron and steel (-2.5%) dropped while the price of softwood lumber (1.1%) and hot rolled steel bars, plates, and structural shapes (2.5%) increased.Chart credit: Associated Builders and ContractorsConstruction materials prices declined slightly in December and are virtually unchanged over the past two years, ABC Chief Economist Anirban Basu said. Of course, there is significant variability across input categories. Much of the recent moderation can be tracked to lower energy prices; diesel prices, for instance, are down rou...