信息不对称、过度自信与股价变动

信息传导的非同步和投资者情绪变化是股票市场的两个典型特征,前者会引发投资者之间出现信息不对称问题,后者主要体现为投资者过度自信,两者共同作用影响股票价格变动。本文将信息不对称和投资者过度自信情绪置于同一个分析框架,建立两阶段动态序贯定价理论模型研究现实市场上信息传导过程中股价变动的内在机制。结果表明:(1)面临新信息的进入,投资者对股票收益预期的调整与均衡价格之间具有正相关关系;(2)面临有利消息时,过度自信投资者比例越大,股票的均衡价格越高,投资收益将越低;面临不利消息时则相反;(3)随着过度自信投资者比例以及过度自信程度升高,市场风险溢价将下降;(4)投资者群体在信息传导过程中出现分化,对股价变动形成异质信念,未获取信息和获取信息但未出现过度自信的投资者认为股价被高估,获取信息且出现过度自信的投资者认为价格被低估,促使更多的交易,引发市场成交量和股价变动;(5)过度自信投资者比例与过度自信程度提高均会对市场效率产生正向影响,而对市场深度具有负向效应。最后,基于理论结果对非对称性和持续性等典型的市场波动性特征进行解释。     

What factors affect behavioral biases? Evidence from Turkish individual stock investors

This paper investigates behavioral biases among Turkish individual stock investors during 2011. Using transaction data, we analyze how common disposition effect, familiarity bias, representativeness heuristic, and status quo bias are, what factors affect these biases and how these biases relate to each other including overconfidence and return performance. We find that biases are common among investors. Male, younger investors, investors with lower portfolio value, and investors in low income, low education regions exhibit more familiarity bias. Female, older investors and investors with high portfolio values are more subject to disposition effect and representativeness heuristic. Individuals in the opposite edge of overconfidence are subject to status quo bias. Overconfidence is positively correlated with familiarity bias. Representativeness heuristic deteriorates wealth while status quo bias results in higher trade performance. Familiarity bias has a nonmonotonic effect on return; lower (higher) levels of familiarity bias have a negative (positive) effect on return. To the best of our knowledge, this is one of the few studies that focus on nationwide data and analyze the biases simultaneously. Using a unique dataset, we extend the findings of the behavioral finance literature to emerging markets. Besides, analysis of multiple biases helps us better understand the relationship among biases.     

Overconfidence and emotion regulation failure: How overconfidence leads to the disposition effect in consumer investment behaviour

Investment decisions and outcomes often entail a myriad of emotions. In this article, the authors examine overconfidence and its effect on investment behaviour. The authors show that overconfident investors tend to trade in greater volumes and exhibit stronger disposition effect. Previous research has shown disposition effect to be an outcome of loss aversion and lack of self-control, and this article shows that the disposition effect is also caused by emotions such as ‘pride’ and ‘shame’, which shows up to a greater degree in overconfident people. Overconfident consumers are prone to realize gains early, in order to feel pride and hold on to losing stocks because admitting losses creates shame. It is also shown that overconfident investors trade in greater volumes and have greater ‘illusion of control’.     

股权激励对企业非效率投资行为的影响研究——基于高管过度自信中介效应的视角

基于高管过度自信的视角考量我国上市公司股权激励实施对企业非效率投资行为的影响,结果表明,我国上市公司普遍存在过度投资和投资不足的现象,股权激励能有效抑制过度投资行为,但对企业投资不足现象具有显著的促进作用,同时,高管过度自信会导致企业过度投资行为的发生,相应地会降低投资不足行为的产生;高管过度自信是导致股权激励效果弱化的重要原因,股权激励的实施会在高管过度自信的作用下加剧企业过度投资行为,而对投资不足表现出不显著的抑制效果;良好的公司治理环境能有效抑制高管过度自信概率,也是激励效果得以发挥的重要前提。     

投资者情绪是导致我国投资者对市场信息出现反应偏差的原因吗：基于贝叶斯分位数回归模型的研究

本文使用贝叶斯分位数回归模型实证分析包含投资者情绪的投资者最优选择模型,结果表明：投资者情绪对于股票收益率存在非线性的正向影响,这是造成投资者对于市场信息出现反应偏差的一个重要原因.同时,市场信息和投资者情绪指标对于我国股票收益率都有着较大的影响作用;当股票出现不同涨跌幅时,市场信息对于股票收益率的影响有着较大的差异性.而考虑了投资者情绪指标之后,投资者对于市场信息的反应偏差明显减小,说明投资者情绪是造成我国投资者对于市场信息出现过度反应和反应不足的重要原因.我国投资者应该树立起良好的投资意识和心态,避免潜在的投资损失.     

Time-varying managerial overconfidence and corporate debt maturity structure

We examine the impact of managerial overconfidence on corporate debt maturity. We build upon the argument that managerial overconfidence is likely to mitigate the underinvestment problem, which is often the major concern for long-term debt investors. Within this context, we hypothesise that managerial overconfidence increases debt maturity. Our empirical evidence, based on time-varying measures of overconfidence derived from computational linguistic analysis and directors’ dealings in their own companies’ shares, supports this hypothesis. Specifically, we find that the changes in both first person singular pronouns and optimistic tone are positively related to the change in debt maturity. Moreover, we find that the insider trading-based overconfidence of CEO, who is most likely to influence investment decision and thus the underinvestment problem, has a stronger impact on debt maturity than the overconfidence of other directors (e.g. CFO). Overall, our study provides initial evidence for a positive overconfidence-debt maturity relation via overconfidence mitigating the agency cost of long-term debt.     

Arrogance can be a virtue: Overconfidence,information acquisition,and market efficiency

In behavioral finance, overconfidence has been established as a prevalent psychological bias, which can make markets less efficient by creating mispricing in the form of excess volatility and return predictability. In this paper, we develop a model in which overconfidence causes investors to overinvest in information acquisition when this information could improve market efficiency by driving prices closer to true values. We study the impact of overconfidence on mispricing and information acquisition, comparing their net effect on prices. We derive several novel implications. First, overconfidence generally improves market pricing provided the level of overconfidence is not too high. Pricing can also improve even when overconfidence is arbitrarily high, depending on the amount of private information acquired relative to publicly available information.     

Home bias in portfolio choices: social learning among partially informed agents

Using an ‘incomplete information’ model, we explore the role of social learning in the global portfolio choices of stock market investors. When partially informed followers attempt to estimate true domestic (home) mean returns, they likely acquire private domestic signals from partially informed leaders. However, the calibration results indicate the existence of home bias when partially informed agents have poor quality information. Partially informed agents are prone to a learning bias; they overreact to new domestic information due to overconfidence in their domestic private signals, but they demonstrate a conservative response to new information in foreign markets. Links between the private signals of partially informed agents may lead to correlated foreign investment strategies among such agents through social learning. We suggest the acquisition of private signals, along with the dissemination of information, affect international portfolio decision rules and are determinants of the phenomenon of home bias.     

Investigation of investors' overconfidence, familiarity and socialization

This study, using a sample of New Zealand investors, investigates three behavioural finance theories: investor overconfidence, socialization and the familiarity effect. We find support for the investor overconfidence theory, using characteristics such as past success, optimism, confidence in one's abilities, investment experience and investment‐related knowledge. Concerning the socialization theory, we observe that the investors actively sought information regarding the stock market, 75 per cent doing this on a weekly basis. Those investors that kept themselves informed daily outperformed other investors by 8 per cent. The familiarity effect was confirmed, showing investors to hold a far too high proportion of local stocks, although the majority of investors believed international equity markets would provide returns that were either better or equal to New Zealand stocks.     

Are Happy Investors Likely to Be Overconfident?

This study investigates the relationship of investors' happy sentiment and overconfidence effect. Sunshine, temperature, former returns, and margin loan change rate are used as proxies for happy sentiment. Using data from Taiwan Stock Exchange and principal component analysis, the happy sentiment index is divided into two categories: "natural environment happiness" and "investment atmosphere happiness." The results suggest that when natural environment happiness is stronger, investors are less likely to have overconfidence. On the contrary, when investment atmosphere happiness is stronger, investors are more likely to have overconfidence.     

A behavioral analysis of investor diversification

This paper studies the link between individual investors’ portfolio diversification levels and various personal traits that proxy informational advantages and overconfidence. The analysis is based on objective data from the largest Turkish brokerage house tracking 59,951 individual investors’ accounts with a total of 3,248,654 million transactions over the period 2008–2010. Wealthier, highly educated, older investors working in the finance sector and those trading relatively often show higher diversification levels possibly because they are better equipped to obtain and process information. Finance professionals, married investors, and those placing high-volume orders through investment centers show poorer diversification possibly as a reflection of overconfidence. Our analysis reveals important nonlinear effects, implying that the marginal impact of overconfidence on diversification is not uniform across investors but varies according to the investor's information gathering and processing abilities.     

The Value of Adjusting the Bias in Recommendations: International Evidence

The financial literature has shown that both earnings forecasts and investment recommendations are optimistically biased. However, while the bias in earnings forecasts has decreased over time and even some recent studies show that they are no longer optimistic, in the case of investment recommendations this bias still remains relatively constant over time. Therefore, it seems that recommendations are less credible to investors than earnings forecasts. The vast majority of recommendation studies have been carried out at the country level. In this paper, we use an international context to study whether profitable investment strategies exist when adjusting the recommendation bias of each analysed country. The adjustment we propose to correct this bias takes into account the differences across countries, and also varies in time to correct for the changes in bias over time within countries. Our empirical results show that there are in fact significant differences in the level of bias among countries, with the US and the UK being the countries with the highest bias. Second, the adjusted consensus portfolios are more orthogonal to typical investment styles (size, book‐to‐market and attention) and we find that investors could implement a higher number of profitable investment strategies using this adjusted measure. In this line, the results show that the countries with the lowest bias obtain the highest risk adjusted abnormal returns. Third, our work entails a practical implication, as it shows the value embedded in a simple necessary adjustment in the global asset management context. This is an important result showing that profitable investment strategies exist when considering a global portfolio based on adjusted recommendations.     

Overconfidence and trading volume

Theoretical models predict that overconfident investors will trade more than rational investors. We directly test this hypothesis by correlating individual overconfidence scores with several measures of trading volume of individual investors. Approximately 3,000 online broker investors were asked to answer an internet questionnaire which was designed to measure various facets of overconfidence (miscalibration, volatility estimates, better than average effect). The measures of trading volume were calculated by the trades of 215 individual investors who answered the questionnaire. We find that investors who think that they are above average in terms of investment skills or past performance (but who did not have above average performance in the past) trade more. Measures of miscalibration are, contrary to theory, unrelated to measures of trading volume. This result is striking as theoretical models that incorporate overconfident investors mainly motivate this assumption by the calibration literature and model overconfidence as underestimation of the variance of signals. In connection with other recent findings, we conclude that the usual way of motivating and modeling overconfidence which is mainly based on the calibration literature has to be treated with caution. Moreover, our way of empirically evaluating behavioral finance models—the correlation of economic and psychological variables and the combination of psychometric measures of judgment biases (such as overconfidence scores) and field data—seems to be a promising way to better understand which psychological phenomena actually drive economic behavior.

投资者教育发挥作用了吗?——来自公募基金个人投资者调查数据的证据

投资者教育是保障资本市场平稳运行、良性发展的重要举措,也是我国资本市场重要的基础性制度建设。本文利用20000多份全国公募基金个人投资者调查数据,分析了投资者教育对基金投资收益的影响,并基于行为金融学框架探究了其背后的作用机制。以往文献研究表明,金融知识水平对投资收益会产生显著影响,本文研究发现,获取金融知识的渠道也会影响投资收益。相对于自己学习金融知识、相关工作经验累积金融知识、向亲戚朋友学习金融知识,投资者教育(如参加金融机构的投资教育活动、接受金融经济类课程或培训)更有助于投资者缓解趋势追逐、频繁交易、处置效应等交易行为偏差,从而获得更高的投资收益。进一步分析表明,投资者教育通过提高“理性程度”来提升基金投资盈利概率、投资总收益率和年均收益率的中介效应分别为19.41%、17.09%和12.75%。此外,不同群体参与投资者教育的积极性和受教育效果存在显著差异,投资者教育要更多采取“分类教育”的形式。本文研究对进一步加强投资者教育、更好地推动资本市场发展具有一定的参考意义。     

The overconfidence of investors in the primary market

We analyze the investment performance of 6993 investors bidding in 77 discriminatory IPO auctions in the Taiwan stock market between January 1996 and April 2000, and find that frequent bidders in these auctions have lower returns than infrequent bidders. The frequent bidders bid too aggressively and evaluate the IPO firms too optimistically, resulting in inferior performance. Despite being quite successful in their first few auction bids, the returns for frequent investors are gradually reduced in subsequent auctions. The multivariate model and the analysis of the possibility of perverse incentives of brokerage firms suggest that our findings cannot be explained by rational hypotheses, whereas in contrast, the theories on overconfidence and self-attribution bias can explain the increase in bidding frequency and the deterioration in return performance for bidders in IPO auctions.     

Capital investment and momentum strategies

The main purpose of this paper is to investigate whether capital investment can affect stock price momentum. We provide empirical evidence that momentum strategies tend to be more profitable for stocks with large capital investment or investment changes. We present a simple explanation for our empirical results and show that our finding is consistent with the behavioral finance theory that characterizes investors?? increased psychological bias and the more limited arbitrage opportunity when the estimation of firm value becomes more difficult or less accurate.     

Endogenous overconfidence in managerial forecasts

We examine whether attribution bias leads managers who have experienced short-term forecasting success to become overconfident in their ability to forecast future earnings. Importantly, this form of overconfidence is endogenous and dynamic. We also examine the effect of this cognitive bias on the managerial credibility. Consistent with the existence of dynamic overconfidence, managers who have predicted earnings accurately in the previous four quarters are less accurate in their subsequent earnings predictions. These managers also display greater divergence from the analyst consensus and are more precise. Lastly, investors and analysts react less strongly to forecasts issued by overconfident managers.     

CEO overconfidence and corporate cash holdings

This study proposes chief executive officer (CEO) overconfidence to be an alternative explanation to corporate cash holdings. We find positive effects of CEO overconfidence on the level of cash holdings and the value of cash, which are mainly due to the investment environments faced by firms. The positive effects of CEO overconfidence on cash holdings level and cash value are barely affected by the traditional motives of cash holdings based on trade-off and agency theories. The analysis of cash sources further explains why firms with overconfident CEOs can aggressively pursue risky investments and maintain large cash holdings at the same time. Although the prior literature indicates that overconfident CEOs tend to avoid equity issues for their capital investments, the contribution to cash savings from equity is higher than that from debt. Additional robustness tests also support our empirical findings.     

Determinants of individual investment decisions in investment‐based crowdfunding

We investigate determinants of investment decisions in investment‐based (equity and bond) crowdfunding campaigns, using a novel investment‐, investor‐ and campaign‐level database, where equity refers to investments in entrepreneurial start‐ups and bonds to large real estate projects. We find that investors who have higher social interactions invest more. Social interactions are important in an equity crowdfunding context but do not affect participation in bond investments. This is consistent with the view that investors' social networks help reduce information asymmetry. Women invest less in the riskiest (equity) investments but more in safer ones (bonds). These findings are better explained by differences in risk aversion than differences in overconfidence between men and women. Overall, the findings contribute to the understanding of how investment‐based crowdfunding can be a viable source of entrepreneurial finance and how entrepreneurs' campaign decisions affect investor participation in this new form of entrepreneurial finance.     

信息透明度与散户的交易选择——基于深圳交易所上市公司的实证研究

股市的风险往往归因于散户的交易,大力发展机构投资者成为提高市场效率的不可挑战的信条。透过微结构数据的分析,本文发现散户交易存在过度自信特征,可能过度高估私有信息精确度,导致错误定价信息。分离了过度自信的因素后,本文发现信息透明度为散户交易的重要依据。更为重要的是本文发现,相对于散户而言,信息透明度对机构投资者交易的影响较低,说明了信息透明度对处于信息劣势的投资者具有更重要的现实意义。