Consider the components model of Section 2.3 but suppose now that there is a fourth consumer named BA whose “ideal” system is XBYA. Answer the following questions.

(a) Calculate the UPE prices and profit levels assuming that the systems are incompatible. Hint: Consider an equilibrium where firm A sells to consumers AA, AB, and BA, whereas firm B sells to consumer BB only.

(b) Calculate the UPE prices and profit levels assuming that the systems are compatible.