Asset pricing with heterogeneous beliefs and relative performance

We propose an equilibrium asset pricing model in which agents with heterogeneous beliefs care about relative performance. We find that the concern with relative performance leads agents to trade more similarly, a development that has two effects. First, similar trading directly decreases volatility. Second, similar trading decreases the impact of dominant agents. The second effect dominates the first when agents expect large differences between their final performances, and vice versa when agents expect small differences between their final performances. Compared with the case in which agents are unconcerned about relative performance, the stock return volatility is higher when the second effect dominates, and lower when the first effect dominates. This paper also demonstrates that the concern about relative performance influences investors’ holdings, stock prices and risk premia.     

Where are the sources of stock market mispricing and excess volatility?

Using a simple dividend model, we illustrate and synthesize the sources of stock market mispricing and excess volatility based upon two hypotheses—inflation illusion and heterogeneous beliefs. Our theoretical framework posits that equity mispricing arises when investors have subjective expectations about discount rates or dividend growth rates. We then analyze the sources of equity mispricing and market excess volatility under a VAR framework. Empirically, we find that both inflation illusion and heterogeneous beliefs explain equity mispricing. However, heterogeneous beliefs play a more important role in explaining stock mispricing in the long run. We also find that heterogeneous beliefs cause excess volatility, but inflation illusion does not. Therefore, dispersion in investors’ beliefs is a better explanation of stock market mispricing than the investors’ inability to properly discount future cash flows.     

Asset pricing with heterogeneous beliefs

This paper studies the dynamic behavior of security prices in the presence of investors’ heterogeneous beliefs. We provide a tractable continuous-time pure-exchange model and highlight the mechanism through which investors’ differences of opinion enter into security prices. In the determination of equilibrium, we employ a representative investor with stochastic weights and solve for all economic quantities in closed form, including the perceived market prices of risk and interest rate. The basic analysis is generalized to incorporate multiple sources of risk, disagreement about nonfundamentals, and multiple investors. Other applications involving multiple goods and nominal asset pricing within monetary economies are discussed.     

投资者异质后验信念对股票价格影响的实证研究

过度自信程度不同的投资者因消息确认精度差异引起意见分歧,产生异质后验信念,导致投资者对股价高估或者低估。在此基础上,以盈余公告信息作为利好或利空消息,研究不同环境下异质后验信念对我国股票价格的影响。实证结果表明:不管在牛市还是在熊市环境下,异质后验信念均会对股价产生影响,当盈余公告为利好消息时,异质后验信念程度越高,当期股价被高估的程度越显著;当盈余公告为利空消息时,异质后验信念程度越高,当期股价被低估的程度越显著。此外,在盈余公告前投资者就对盈余消息作出了反映,但对好消息与坏消息的反映程度不同。     

An evolutionary CAPM under heterogeneous beliefs

Heterogeneity and evolutionary behaviour of investors are two of the most important characteristics of financial markets. This paper incorporates the adaptive behaviour of agents with heterogeneous beliefs and establishes an evolutionary capital asset pricing model (ECAPM) within the mean-variance framework. We show that the rational behaviour of agents switching to better-performing trading strategies can cause large deviations of the market price from the fundamental value of one asset to spill over to other assets. Also, this spill-over effect is associated with high trading volumes and persistent volatility characterized by significantly decaying autocorrelations of, and positive correlation between, price volatility and trading volume.     

Can earnings fixated investors survive in a competitive securities market? Implications for sustained price anomalies and mark-to-market accounting

We model the dynamic survival of earnings fixated investors in a competitive securities market that allows for learning and arbitrage and that is populated by heterogeneous investors. Our model is distinct from those based on aggressive trading by overconfident investors. We prove that in the absence of noise traders, rational investors will drive out earnings fixated investors from the market in the long-run. More interestingly, we show that in a market with noise traders, some proportion of earnings fixated investors survive in long-run equilibrium for all feasible model parameter values. Furthermore, under no circumstances can the earnings fixated investors be driven out of the market completely. On the contrary, for some parameter values, the earnings fixated investors drive out the rational investors entirely. These results rationalize the long-run sustainability of common pricing anomalies. They also highlight potential benefits to society of mark-to-market accounting.     

Market Created Risk

We develop a multiperiod rational expectations model of securities market equilibrium in which equilibrium prices may move between periods even though it is common knowledge that no new information has arrived about ultimate security payoffs. This happens because investors know they have imperfect information about the endowments of other investors and this knowledge affects their probability beliefs about the prices that will prevail at the intermediate trading date. These beliefs are reflected in the equilibrium at the initial trading date when investors focus on the probabilities of intermediate capital gains and losses, rather than ultimate payoffs.     

Investors’ heterogeneous beliefs and the impact of sovereign credit ratings in foreign exchange and equity markets

We propose a model in which sovereign credit news from multiple rating agencies interacts with market heterogeneity. The model illustrates that the first messenger discloses new information while additional messengers play an important role of coordinating heterogeneous beliefs. Empirical investigations based on sovereign credit ratings, foreign exchange and equity markets confirm that rating news coordinates investors’ beliefs. Sovereign credit rating news from both types of messenger induces a significant impact on exchange rates and stock indices. Volatility measures increase in response to news from the first messenger while ex-post volatility reduces following news from an additional messenger.     

Noise Trading in Small Markets

Considering noise traders as agents with unpredictable beliefs, we show that in an imperfectly competitive market with risk averse investors, noise traders may earn higher expected utility than rational investors. This happens when, by deviating from the Nash equilibrium strategy, noise traders hurt rational investors more than themselves. It follows that the willingness of arbitrageurs to exploit noise traders' misperceptions is lower relative to a perfectly competitive economy. This result reinforces the theory that noise trading may explain closed-end fund discounts and small firms' returns, since these markets are less competitive than the market for large firms' stock.     

Inconsistent Signals,Earnings Announcements,and Market Uncertainty

We test the proposition in Johnstone (2016) that new information may lead to higher, rather than lower, uncertainty about firms’ future payoffs. Based on the Bayesian rule, we hypothesize earnings news that is inconsistent with investors’ prior belief will lead to higher market uncertainty. Using earnings signals in the past few quarters to proxy for investors’ prior belief, we find supporting evidence that, relative to consistent earnings news, inconsistent news results in an increase in market uncertainty measured by implied volatility. Inconsistent earnings news has a larger effect on market uncertainty when prior beliefs are stronger and when the news is negative. Overall, our evidence highlights the importance of prior belief and inconsistent signals in understanding the effect of earnings news on market uncertainty.