Consider a duopoly for a homogeneous product. Firms i = 1, 2 set price-quantity pairs (p_i, q_i) simultaneously. If at these pairs some consumers are rationed, rationing is assumed to be efficient. Suppose firms are constrained by capacities k_i > 0 and inverse market demand is P (q) = q^-1. Does a Nash equilibrium in pure strategies exist? Is it unique? Characterize all Nash equilibria of this game.