English

Mechanism Design for Investment Regulation under Herding

Mathematical Finance 2026-04-14 v1 Systems and Control Systems and Control

Abstract

Herding, where investors imitate others' decisions rather than relying on their own analysis, is a prevalent phenomenon in financial markets. Excessive herding distorts rational decisions, amplifies volatility, and can be exploited by manipulators to harm the market. Traditional regulatory tools, such as information disclosure and transaction restrictions, are often imprecise and lack theoretical guarantees for effectiveness. This calls for a quantitative approach to regulating herding. We propose a regulator-leader-follower trilateral game framework based on optimal control theory to study the complex dynamics among them. The leader makes rational decisions, the follower maximizes utility while aligning with the leader's decisions, whereas the regulator designs a mechanism to maximize social welfare and minimize regulatory cost. We derive the follower's decisions and the regulator's mechanisms, theoretically analyze the impact of regulation on decisions, and investigate effective mechanisms to improve social welfare.

Keywords

Cite

@article{arxiv.2604.11100,
  title  = {Mechanism Design for Investment Regulation under Herding},
  author = {Huisheng Wang and H. Vicky Zhao},
  journal= {arXiv preprint arXiv:2604.11100},
  year   = {2026}
}