Many engineers feel that they are not sufficiently compensated for their work—and that is apparently true when it comes to the 7.1% of them who hold down second jobs. The statistics come from a 1997 National Science Foundation study that examined the demographics of working scientists and engineers who work at two jobs. Money, in fact, could have a lot to do with it. Engineers with a second job reported earnings 20% lower than the average for their counterparts with just a single job. Take note that the study is five years old. These days, many engineers probably would be more than happy to have even one job.