Bloomberg reports that Dow Chemical is leading a record expansion in the U.S. chemical industry as shale gas revives the industry’s economics. Dow is among companies planning to build crackers, industrial plants typically costing $1.5 billion apiece that process hydrocarbons into ethylene and other synthetic materials. The new crackers will be the first to be built in the U.S. since 2001 and the largest wave of additional capacity. Driving this renaissance is the plunge in the price of natural gas, used in crackers as a raw material, to a nine-year low. New drilling methods are opening up vast shale formations from Texas to West Virginia. U.S. chemical investments stemming from shale gas may top $16 billion, creating 17,000 jobs directly and another 400,000 indirectly, according to the American Chemistry Council, a Washington-based industry group.