WASHINGTON — The nation’s unemployment rate climbed to a four-year high of 5.7 percent in July as employers cut 51,000 jobs, dashing the hopes of an influx of young people looking for summer work. Payroll cuts weren’t as deep as the 72,000 predicted by economists, however. And, job losses for both May and June were smaller than previously reported. July’s reductions marked the seventh straight month where employers eliminated jobs. The economy has lost a total of 463,00 jobs so far this year. The latest snapshot, released by the Labor Department on Friday, showed a lack of credit has stunted employers’ expansion plans and willingness to hire. Fallout from the housing slump and high energy prices also are weighing on employers. The increase in the unemployment rate to 5.7 percent, from 5.5 percent in June, in part came as many young people streamed into the labor market looking for summer jobs. This year, fewer of them were able to find work, the government said. The unemployment rate for teenagers jumped to 20.3 percent, the highest since late 1992. Wall Street initially found reason for optimism in the report, but news that General Motors Corp. (GM) […]