13.1. Beryllium oxide is a chemical compound used in pharmaceutical applications. Beryllium oxide can only be made in one particular way, and all firms produce their version of beryllium oxide to the exact same standards of purity and safety. The largest firms have market shares given in the following table:

Firm Market Share Mercury 80%

Mars 1%

Jupiter 1%

Saturn 1%

a) What is the four-firm (4CR) concentration ratio for this industry?

b) What is the Herfindahl-Hirschman Index (HHI) for this industry?

c) Of the market structures described in Table 13.1, which one best describes the beryllium oxide industry?