economics question

Consider an exchange cash-in-advance economy similiar to that studied by Alan Stockman in which the money supply, Mr, grows at the (gross) constant rate # > 0 so that Mr = #M-1. The endowment in this economy is stochastic and can take on two values (x1, x2) with x1 0, u"(q) 0 per unit. What is the economic meaning of ? What is the buyer's optimal choice of m, and how does it depend on