2. Monsanto, the maker of Nutrasweet, owned the patent to aspartame, the official name of the sweetener. In 1987 Monsanto's patent expired in Europe, allowing other firms to produce aspartame under other brand names.

a. What impact do you think this had on the market for aspartame and Monsanto's profits? Comment on the change in market structure and market power.

b. What are some barriers to entry that Monsanto could use to keep its market power? Explain each one.