15. Academic libraries' outputs a. Include circulation only b. Include raw materials and paper inventories c. Include reference service d. Include books and journals only 16. A Dummy variable a. Has one negative value b. Has two negative values c. Has one positive value d. Has two positive values 17. The scholarly journal market is dysfunctional because a. Professors discounted journal prices so the market is full of junk journals b. Some universities cannot afford to pay for journals c. Journal prices are set lower than the costs and inflation d. Journal prices are set lower than the marginal cost 18. An original and empirical economic research project typically a. Uses theories without data b. Uses no hypotheses with regressions c. Uses data points without regressions d. Uses regressions with data points