According to economists, one reason few professional athletes have phd’s is that the: a. marginal cost of going to graduate school is too high. b. explicit cost of going to graduate school would be too high. c. comparative cost of going to graduate school is too high. d. opportunity cost of going to graduate school is too high. e. marginal benefit of going to graduate school is too high.

As the inventor of hypertension medication, onesure pharmaceuticals (osp) inc. was able to reap the benefits of economies of scale due to a large consumer demand for the drug. even when competitors later developed similar drugs after the expiry of osp's patents, regular users did not want to switch because they were concerned about possible side effects. which of the following benefits does this scenario best illustrate? a. first-mover advantages b. social benefits c. network externalities d. fringe benefits