“…Although the seller has a reservation value function, she is assumed to reveal this function truthfully. This is a natural assumption from the well-known impossibility result of Myerson and Satterthwaite (1983), saying that it is impossible to design a trading mechanism even just for one buyer and one seller with one 12 The major differences between Sun and Yang (2014) and the current one are (1) while in the current model there are two sets of items, items of each set are substitutable and can be heterogeneous but are complementary to items in the other set, goods in the model of Sun and Yang (2014) are all complementary; (2) while the current model has a Walrasian equilibrium (Sun and Yang 2006) in which the pricing rule is anonymous and linear, the model of Sun and Yang (2014) can only guarantee the existence of a nonlinear pricing Walrasian equilibrium in which the pricing rule is anonymous but nonlinear; (3) while the current auction is a blend of ascending and descending formats where prices are specified on individual items, the auction of Sun and Yang (2014) is and must be a package auction in which prices are specified on bundles of items; (4) there does not exist any transformation between the current model and Sun and Yang (2014) and in fact the structure of equilibrium price vectors for the two models is inherently different; see Sun and Yang (2009, Theorem 3, p. 937;2014, Theorem 1, p. 432). These two models describe two typical, basic, and closely related yet intrinsically different economic environments.…”