U.S. employers are finding it increasingly difficult to find skilled workers, according to a survey published on Monday, suggesting upward pressure on wage growth down the road. The National Association for Business Economics’ latest business conditions survey found that 35 percent of the 112 economists who participated reported their firms had seen shortages of skilled labor during the quarter ending in July. “The panel reports markedly increased shortages in the July survey, especially of skilled labor,” said survey Chairman Jim Diffley, who is also a senior director at IHS Economics.