I am an assistant professor at Institute of Economics, Academia Sinica.


My field of interest is microeconomic theory, in  particular mechanism design, 

information design and industrial organization.

Here is my CV.

You can contact me at ckwak@econ.sinica.edu.tw.

Working Papers

This paper provides conditions under which a general screening problem can be reduced, without loss to the principal, to one that satisfies the single-crossing property. The reduction requires the principal’s preference to be appropriately ordered relative to that of the agent. In a particular class of environments that extends the standard single-crossing problem to multi-dimensional allocations, the conditions for single-crossing reducibility are readily verified and applied to deliver optimal mechanisms. Analyzing this “pairwise single-crossing problem” generalizes existing results on the optimality of “interval structures” across a wide range of problems, including multi-product monopoly, persuasion, and bilateral trade.

This paper studies a moral hazard problem in which the principal can ex ante commit to an information disclosure policy to control the agent's incentives. The outcome depends on the unverifiable state of nature, in addition to the agent's effort choice. I characterize the principal's optimal disclosure policy. The critical aspect of the problem is the relation between the order of the increase in the success probability by working and the order of the rate of the increase, across states. Necessary and sufficient conditions for the optimality of full and no disclosure are derived. I also discuss intermediate forms of disclosure.

Published and Accepted papers

Taxation and Durable Good Monopoly. (with Jihong Lee)

Journal of Industrial Economics, 2023

This paper studies the role of taxation in durable good markets with dynamic monopolies. By conditioning the marginal tax rate on the volume of trade, the regulator can provide incentives for the monopolist to accelerate trade. When marginal cost pricing generates a loss for the monopolist and the regulator faces a budget constraint, strategic delay cannot be avoided under regulatory budget constraint and the effects of tax policy depend on the monopolist's ability to commit. In the context of binary consumer types, we find a tax policy involving “back-loaded subsidy” that achieves the second-best outcome with commitment. In contrast, without commitment, a “front-loaded subsidy” improves welfare.