If anyone could help, I would grealty appreciate it! I will also rate you. Thanks.

10. To measure the effectiveness of government training programs, it is usual to compare worker's pay before and after training. But many workers sign up for training when their pay drops or they are laid off. So the "before" pay is unusually low and the pay gain looks large. a). Is this bias or random error in measuring the effect of training on pay? Why? b). How would you measure the success of training programs