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.)

Kiona co. set up a petty cash fund for payments of small amounts. the following transactions involving the petty cash fund occurred in may (the last month of the company's fiscal year). may 1 prepared a company check for $350 to establish the petty cash fund. 15 prepared a company check to replenish the fund for the following expenditures made since may 1. a. paid $109.20 for janitorial services. b. paid $89.15 for miscellaneous expenses. c. paid postage expenses of $60.90. d. paid $80.01 to the county gazette (the local newspaper) for an advertisement. e. counted $26.84 remaining in the petty cashbox. 16 prepared a company check for $200 to increase the fund to $550. 31 the petty cashier reports that $380.27 cash remains in the fund. a company check is drawn to replenish the fund for the following expenditures made since may 15. f. paid postage expenses of $59.10. g. reimbursed the office manager for business mileage, $47.05. h. paid $48.58 to deliver merchandise to a customer, terms fob destination. 31 the company decides that the may 16 increase in the fund was too large. it reduces the fund by $50, leaving a total of $500.