A letter report issued by the Government Accountability Office with an abstract that begins "Census data show that U.S. and foreign produced titanium prices varied from 2003 through 2012 depending on the product. For example, in 2012, the export price (the proxy for the U.S. price) for titanium bar--used to make engine blades--was higher than the import price (the proxy for the foreign price), while the export price for titanium sheet--used to make wing components--was less than the import price. Industry officials noted that these differences may be due to varying operating costs and titanium production capabilities in different countries and to titanium producers' negotiated agreements with prime contractors or aircraft component manufacturers."