To test the effectiveness of a job training program on the subsequent wages of workers, we specify the model log1wage2 5 b0 1 b1train 1 b2educ 1 b3exper 1 u, where train is a binary variable equal to unity if a worker participated in the program. Think of the error term u as containing unobserved worker ability. If less able workers have a greater chance of being selected for the program, and you use an OLS analysis, what can you say about the likely bias in the OLS estimator of b1? (Hint: Refer back to Chapter 3.)

Biochemical corp. requires $600,000 in financing over the next three years. the firm can borrow the funds for three years at 10.80 percent interest per year. the ceo decides to do a forecast and predicts that if she utilizes short-term financing instead, she will pay 7.50 percent interest in the first year, 12.15 percent interest in the second year, and 8.25 percent interest in the third year. assume interest is paid in full at the end of each year. a)determine the total interest cost under each plan. a) long term fixed rate: b) short term fixed rate: b) which plan is less costly? a) long term fixed rate plan b) short term variable rate plan