Does job training work? A state institutes a job-training program for manufacturing workers who lose their jobs. Aft er fi ve years, the state reviews how well the program works. Critics claim that, because the state’s unemployment rate for manufacturing workers was 6% when the program began and 10% fi ve years later, the program is ineff ective. Explain why higher unemployment does not necessarily mean that the training program failed. In particular, identify some lurking variables whose eff ect on unemployment may be confounded with the eff ect of the training program. Draw a picture like Figure 6.1 (page 260) to illustrate your explanation.