PC Hyeryeong Park
Junrok Park
Assistant professor of Economics, National Taiwan University.
My research interests lie in information design and mechanism design.
e-mail: parkjunrok@ntu.edu.tw
Research
Buyers-optimal Learning In Collective Purchase Problems
Abstract: A group of buyers plans to collectively purchase an indivisible good from a monopolist seller. The good benefits everyone in the group non-rivalrously and non-exclusively. Each buyer must learn about the good's value before negotiating with the monopolist. Since the good resembles public goods, a received intuition predicts underprovision due to the seller's market power and the buyers' free-riding. This paper solves the Buyers-optimal Learning problem, an information design problem preceding the monopolist's optimal sales mechanism. The solution cross-subsidizes the informational rents among buyers so that the seller finds it optimal to sell the efficient quantity. An explicit solution for the two-buyer case illustrates it in detail. Welfare properties in the large economy are analyzed from a robust prediction perspective. Contrary to the classical negative results, the monopolist's profit can be bounded, while the good is always provided to the buyers.
Double Clock Auctions with Taxes (with Pavel Andreyanov and Tomasz Sadzik) (Reject-and-resubmit at American Economic Review)
Abstract: In a stylized exchange economy with single, continuous good and quasi-linear utilities, we propose a novel double-auction format featuring two (forward and reverse) clock auctions, Vickrey-style payments, and carefully designed per-unit taxes. In the spirit of Ausubel (2004), we show a sincere ex-post perfect equilibrium of the game and that the market-clearing price is the Walrasian equilibrium price in an economy with deformed utilities. Furthermore, we show how the auctioneer can adjust the clocks dynamically to minimize the informational spillover between the two auctions. Finally, we show that the said taxes can implement an optimal robust mechanism in the sense of ex-post IC and IR constraints but ex-ante objectives, such as efficiency or revenue, in private values setting similar to Lu and Robert (2001). Further tractability is achieved given quadratic utilities, allowing for comparisons with the nearly efficient robust mechanisms of Andreyanov and Sadzik (2021).