The price of U.S. lumber will fall further in the coming months as sawmills increase production, though demand is expected to hold strong, according to Capital Economics.  "High prevailing prices have already encouraged lumber mills to boost output and we anticipate that domestic production will rise even further as labor shortages in the trucking and forestry sector dissipate," Samuel Burman, assistant commodities economist, said in a note Wednesday.  The number of rail cars hauling lumber in North America rose above 7,000 for the first time in over two years in May and, "despite slipping ...