This paper seeks to explain why some pharmaceutical companies are observed to withdraw their products before patents are expired and simultaneously introduce new patented (competing) products. Given the specific nature of drug markets, the companies in fact increase the entry cost of the...

In terms of a simple model we show that removal of tariff from a competing foreign brand is likely to expand the size of the domestic industry when income disparities exist. A tariff increases profits of the local monopolist but is capable of cutting down the size of the local industry. After...