The number of people filing new claims for unemployment benefits jumped last week to an 18-month high, as superstorm Sandy dented the economy by leaving tens of thousands of people out of work along the U.S. east coast, the government reported Thursday. The Labor Department said weekly jobless claims increased by 78,000 to 439,000 because a large number of applications were filed in states hit by the storm. People can claim unemployment benefits if their workplaces close and they do not get paid. A department analyst said Sandy, a huge storm that hit the east coast in late October, may distort reports for another two weeks. The storm disrupted businesses from North Carolina to Maine and cut power to about 8 million homes and businesses. Some are still without electricity. The four-week moving average of jobless claims, a less volatile measure considered a better gauge of labor-market trends, increased 11,750 to 383,750. Economists generally believe a reading below 400,000 points to an increase in employment. Before Sandy distorted data, weekly jobless claims had fluctuated between 360,000 and 390,000 since January, but employers were adding almost 157,000 jobs per month, barely enough to reduce the unemployment rate, which was 7.9 percent in October. There are some signs that the labor market is improving. Employers added 171,000 jobs in October, and hiring in September and August was stronger than first estimated. The economy has gained an average of 173,000 jobs a month since July, up from an average of 67,000 a month in the April-June quarter.