4. In the US market for four prescription medicines (analgesic/musculoskeletal, anti-Iipidemics, gastronintestinal acid reducers, and insomnia), the elasticity of demand with respect to consumer advertising ranged between 0.13 and 0.19, while the elasticity of demand with respect to physician advertising was 0.51. The own-price elasticity was -0.67 for drugs advertised to consumers and 0.73 for drugs not advertised to consumers. (Source: Dhaval Dave and Henry Saffer, "Impact of Direct-to- Consumer Advertising on Pharmaceutical Prices and Demand", Southern EconomicJournal, Vol. 79 No. 1, 2012, 97-126.) (a)How would a 5% increase in expenditure on advertising to consumers affect the demand for the four prescription medicines? (b)What about a 5% increase in expenditure on advertising to physicians? (c) Do you expect the same difference between advertising to consumers vis-a-vis physicians in the demand for over-the-counter (non- prescription) medicines? (d)Suppose that a drug manufacturer were to increase advertising. Explain why it should also raise the price of its drugs