讲座题目：Cournot Competition, Informational Feedback, and Real Efficiency （古诺竞争、信息反馈与实体经济效率）

主讲人：李四光 香港科技大学（广州）

讲座时间：2024年11月08日10:00

讲座地点：学院206

讲座内容摘要：

We revisit the relationship between firm competition and real efficiency in a novel setting with informational feedback from financial markets. Although intensified competition can decrease market concentration in production, it reduces the value of proprietary information (e.g., market prospects) for speculators and discourages information production and price discovery in financial markets. Therefore, competition generates non-monotonic welfare effects through two competing channels: market concentration and information production. When information reflected in stock prices is sufficiently valuable for production decisions, competition can harm both consumer welfare and real efficiency. Our results are robust under cross-asset trading and learning and highlight the importance of considering the interaction between product market and financial market in antitrust policy, e.g., concerning the regulation of horizontal mergers.

本文将金融市场的信息反馈效应嵌入到古诺竞争中，并讨论公司竞争与实体经济效率间的关系。竞争的加剧会降低生产过程中的市场集中度，但也会减少专有信息（如市场前景）对投机者的价值，并抑制金融市场中的信息生产和价格发现。因此，竞争会通过市场集中度和信息生产两个作用机制影响实体经济效率，并带来非单调的福利效应。当股价所反馈的信息对生产决策足够重要时，竞争甚至可能会损害消费者福利和实际效率。在考虑跨资产交易和跨资产学习后，基本结论也是稳健的，并强调了在反垄断政策中考虑产品市场和金融市场之间相互作用的重要性。本文对于横向并购与反垄断具有政策含义。

主讲人学术简介：

李四光，康奈尔大学经济学博士，目前就职于香港科技大学（广州）。曾在Journal of Economic Theory, International Economic Review, 《经济研究》，Finance and Stochastics, Quantitative Finance等杂志发表10余篇论文。