噪音与证券分析师的迎合动机

Noise and Financial Analysts＇ Catering Incentives

证券分析师是市场解读信息的重要力量。然而最近的研究表明，分析师意见存在系统性的偏差。鉴于此，探讨分析师意见偏差背后的行为动机，剖析分析师意见对证券价格的影响便具有重要意义。本文应用迎合理论，构建分析师与投资者之间的理性博弈模型，证明了在投资者具有信息劣势的博弈中，分析师的迎合动机会放大噪音对其购买意见以及均衡价格的影响。理性投资者并未能消除分析师迎合动机造成的股价噪音，从而从分析师角度，为股价对噪音的过度反应找到了一种理性的微观机制。

Financial Analysts have been important information processors in financial markets. Recent empirical studies, however, suggest that analysts＇ opinions （i. c. forecasts and recommendations） are biased. It is therefore of great reference value to investigate what drives the biases of analysts＇ opinions and to analyze the impact the analysts＇ opinions have on stock price. This paper builds a game-theoretic model between rational investors and analysts with catering incentives and proves that in equilibrium when investors lack information about new investment opportunities, catering incentive would exaggerate the impact of noise on both analysts＇ opinions and stock price. The model also predicts that investors＇ rationality cannot eliminate the noise caused by analyst＇s catering incentives. From this perspective, we find a rational micro-mechanism for overreaction of stock price to noise based on the analysis of analysts＇ behavior.