投资者异质性与证券市场定价——理论模型与中国的经验证据

本文从投资者异质性的客观现实出发,通过对投资者二维视角的交叉分类与相关行为的探讨,提出了一种按交易特点与行为依据的新的分类方案,即将投资者分为套利交易者、价格预期交易者和量能变动交易者三类。在此基础上分别建立了各类投资者的需求函数,通过对证券市场供求函数的讨论,利用均衡分析方法构建了基于投资者异质性的证券市场定价模型,并以我国证券市场1999-2011年的月度数据为样本进行了实证分析。实证结果表明:我国证券市场价格主要由价格预期交易者的诱导性策略行为与量能变动交易者的羊群行为决定,套利交易者的套利行为对市场价格没有显著的影响,证券市场扩容也未对市场价格的形成产生系统性冲击。     

Interpreting Factor Models

We argue that tests of reduced‐form factor models and horse races between “characteristics” and “covariances” cannot discriminate between alternative models of investor beliefs. Since asset returns have substantial commonality, absence of near‐arbitrage opportunities implies that the stochastic discount factor can be represented as a function of a few dominant sources of return variation. As long as some arbitrageurs are present, this conclusion applies even in an economy in which all cross‐sectional variation in expected returns is caused by sentiment. Sentiment‐investor demand results in substantial mispricing only if arbitrageurs are exposed to factor risk when taking the other side of these trades.     

Diversification and heterogeneity of investor beliefs

In the paper, we find that diversification reduces the heterogeneity of investor beliefs on firm value. We obtain this finding by comparing not only between diversified and focused firms but also between diversifying and non-diversifying mergers. We also find that the reduced heterogeneity of investor beliefs on a diversified firm relative to its focused peers is negatively associated with its contemporaneous excess value and positively associated with its future excess value. Overall, our results contribute to the understanding about how corporate organization structure affects the heterogeneity of investor beliefs and further firm value.     

Connecting two markets: An equilibrium framework for shorts,longs, and stock loans

We analyze a reduced-form framework for understanding the equity loan market's impact on share prices. We show that hard-to-borrow stocks will have distinct return patterns, responding more to shocks in the supply of shares available, and to changes in the heterogeneity of investor beliefs, than other stocks. We conduct two empirical tests in which we find strong support for these equilibrium predictions. In our first test, we take advantage of a tax-driven exogenous shock to share loan supply and find that when supply is reduced around dividend record dates, prices of hard-to-borrow stocks increase 1.1% while prices of easy-to-borrow stocks are unaffected. In our second test, we find that hard-to-borrow stocks have 4.8% lower three-month returns than other stocks, with negative returns concentrated in stocks with high heterogeneity in investor beliefs. Thus, we extend the Diether, Malloy, and Scherbina (2002) result that stocks with a greater dispersion of investor beliefs have lower returns.     

Analyst following of privatized firms around the world: The role of institutions and ownership structure

We examine which factors affect the decision of analysts to follow newly privatized firms as well as the factors that determine the extent of that following. Contrary to traditional private firms, privatized firms harbor particular uncertainties related to the government's commitment toward privatization. The first-stage estimation shows that the decision by analysts to initiate coverage of newly privatized firms is positively influenced by lower political risk, better judicial efficiency, better information disclosure, and effective extra-legal institutions in the country. Conditional on the decision to initiate coverage, the second-stage results indicate that the extent of analyst following is more important: (1) when there is control relinquishment by the government, (2) when there is more participation by foreign investors and employees, and (3) for those larger firms in nonstrategic sectors. Finally, analysts' coverage is negatively related to postprivatization ownership concentration and underpricing. This latter result runs counter to the existing evidence on private firms—that is, that underpricing “buys” coverage.     

Orderbook demand for corporate bonds

We examine the determinants of investor demand for corporate bond offerings using novel data on the primary market orderbook size. We find that credit risk and bond market presence are significant in explaining investor demand. These effects are more pronounced during the crisis periods including the global financial crisis and eurozone crisis as well as during the postcrisis periods. Our results also highlight the size of the bond investor order depends on information asymmetry costs and the benefit of diversifications, as investor demand is lower for new issuers as well as very frequent issuers. The levels of investor demand have important economic consequences for bond issuers as high investor demand shortens the time to subsequent bond issues and potentially reduces the firm's cost of capital at issuance.     

Corporate Fraud and Business Conditions: Evidence from IPOs

We examine how a firm's incentive to commit fraud when going public varies with investor beliefs about industry business conditions. Fraud propensity increases with the level of investor beliefs about industry prospects but decreases when beliefs are extremely high. We find that two mechanisms are at work: monitoring by investors and short‐term executive compensation, both of which vary with investor beliefs about industry prospects. We also find that monitoring incentives of investors and underwriters differ. Our results are consistent with models of investor beliefs and corporate fraud, and suggest that regulators and auditors should be vigilant for fraud during booms.     

Taxes,tenders and the design of Australian off‐market share repurchases

In designing off‐market (self‐tender offer) share repurchases, Australian companies must consider the resulting potential tax benefits for different investor groups with consequent effects upon the supply of stock tendered by holders and the ultimate tender outcome. We develop and estimate a model of the stock supply curve that demonstrates less than perfect elasticity and incomplete tax arbitrage arising from ‘participation risk’ for potential arbitrageurs. We are able to estimate the extent of disequilibrium in prices involved in fixed‐price repurchases and show that it is substantial. We show that Australian Tax Office restrictions on the tender price range for Dutch auctions have meant that non‐participating shareholders have foregone some potential benefits through the transfer of tax benefits to (primarily institutional, low tax rate) successful tender participants. The results provide support for legislative changes proposed in 2009 (but not implemented as of mid 2011), which removed constraints on the allowable range of repurchase prices.     

Is “voting with your feet” an effective mutual fund governance mechanism?

Investors in open-end mutual funds can vote with their feet by withdrawing assets from or adding assets to these funds. This paper assesses the effectiveness of this market discipline mechanism by investigating whether voting with the feet prevents the abusive practices that led to the 2003-2004 trading scandals. The research results indicate that funds with higher flow sensitivity—that is, a higher density of vigilant clients—have lower arbitrage potential and fewer abnormal flows, which in turn implies less opportunistic trading. As a result, these funds have a lower probability of being implicated in scandals. These findings suggest that investor ability to withdraw assets from or add assets to the funds is an effective mutual fund governance mechanism. In funds with less sophisticated investors who cannot use this option, other means of governance are especially important.     

A profit-maximizing model of Federal Home Loan Bank behavior

In this article the price-setting behavior of the district Federal Home Loan Banks (FHLBs) is investigated. Previous studies have viewed the FHLB system as a policy authority that sets the interest rate on FHLB advances in an attempt to stabilize mortgage and housing markets. In this study a profit-maximizing model of FHLB behavior is developed and empirically tested, and the results compared to a model of the FHLB system as a policy authority. The empirical results offer support for the hypothesis of profit-maximizing behavior and indicate that, in addition to the FHLB's cost of funds, factors that influence thrift demand for FHLB advances, deposits, and capital stock are important in explaining FHLB choice variables.     

Complex Asset Markets

Investors' individual arbitrage models introduce idiosyncratic risk into complex asset strategies, driving up average returns and Sharpe ratios. However, despite the attractive risk-return trade-off, participation is limited. This is because effective Sharpe ratios in complex asset markets vary with investors' expertise. Investors with higher expertise, better models, and lower resulting idiosyncratic risk exposures realize higher Sharpe ratios. Their demand deters entry by less sophisticated investors. As predicted by our model, market dislocations are characterized by an increase in idiosyncratic risk, investor exit, and persistently elevated alphas and Sharpe ratios. The selection effect from higher expertise agents' more favorable Sharpe ratios is unique to our model and key to our main results.     

Long term dependence in stock returns

We show, using the modified rescaled range statistic, that none of the return series of indices of five European countries, the United States and Japan exhibits long term dependence. This statistic — introduced by Lo (1991) — correct Hurst's (1951) ‘classical’ rescaled range statistic for short term dependence. We also report the classical rescaled range statistic after adjusting the series for short term dependence. This procedure shows, for cases where the results of the modified rescaled range statistic are mixed, that no long term dependence can be found. Simulations indicate reasonable power of this adjustment procedure. Furthermore, we find that estimates of the Hurst exponent, a related measure of long term dependence, are also biased by short term dependence. Simulations show that this measure — that has recently attracted growing interest — cannot distinguish between models with or without long term dependence.     

The Federal Home Loan Bank System: The Lender of Next‐to‐Last Resort?

The Federal Home Loan Bank (FHLB) System is a large cooperatively owned government‐sponsored liquidity facility that lends predominately to U.S. depository institutions. This paper documents the significant role played by the FHLB System at the outset of the recent financial crisis and provides evidence on the uses of FHLB funding by member banks and thrifts during that time. We then compare lending activity by the FHLB System and the Federal Reserve during 2007 and 2008, discuss the types of institutions seeking government‐sponsored liquidity at various times, and identify the trade‐offs faced by borrowers eligible to tap liquidity from both facilities.     

Investor Heterogeneity and the Cross-section of U.K. Investment Trust Performance

We use the upper and lower bounds derived by Ferson and Lin (2010) to examine the impact of investor heterogeneity on the performance of U.K. investment trusts relative to alternative linear factor models. We find using the upper bounds that investor heterogeneity has an important impact for nearly all investment trusts. The upper bounds are large in economic terms and significantly different from zero. We find no evidence of any trusts where all investors agree on the sign of performance beyond what we expect by chance. Using the lower bound, we find that trusts with a larger disagreement about trust performance have a weaker relation between the trust premium and past Net Asset Value (NAV) performance.     

Robust consumption and portfolio choice for time varying investment opportunities

This paper examines a continuous-time intertemporal consumption and portfolio choice problem for an investor with recursive preferences. The investor worries about model misspecification and seeks robust decision rules. The expected excess return of a risky asset follows a mean-reverting process. I find that whether the concern about model misspecification decreases the total demand for equities largely depends on risk aversion and the attitude toward intertemporal substitution. When the elasticity of intertemporal substitution is about 1 and risk aversion is moderate, the aversion to model uncertainty increases the proportion of wealth invested in equities. The calibration analysis based on detection-error probabilities shows that the quantitative effect of robustness is almost negligible.     

Post Bretton Woods deviations from purchasing power parity in G7 exchange rates—an empirical exploration

Exchange rates have deviated substantially and idiosyncratically from purchasing power parity (PPP) since the breakdown of Bretton Woods. In this paper, a model incorporating both traditional PPP and financial market variables is constructed and tested on the US dollar's six G7 exchange rates during the floating rate era. Empirical tests show that the model's common set of variables—with consistent signs—can explain the divergent behavior of G7 exchange rates during 1973.2–90.2. Idiosyncracies are reflected in different subsets of the model's variables entering significantly into each exchange rate's regression; the existence of stable relationships is demonstrated by the equations' co-integration.     

Left-tail momentum: Underreaction to bad news,costly arbitrage and equity returns

This paper documents a significantly negative cross-sectional relation between left-tail risk and future returns on individual stocks trading in the US and international countries. We provide a behavioral explanation to this anomaly based on the idea that investors underestimate the persistence in left-tail risk and overprice stocks with large recent losses. Thus, low returns in the left-tail of the distribution persist into the future causing left-tail return momentum. We find that the left-tail risk anomaly is stronger for stocks that are more likely to be held by retail investors, that receive less investor attention, and that are costlier to arbitrage.     

Exchange rate dynamics under alternative optimal interest rate rules

We explore the role of interest rate policy in the exchange rate determination process. Specifically, we derive exchange rate equations from interest rate rules that are theoretically optimal under a few alternative settings. The exchange rate equation depends on its underlying interest rule and its performance could vary across evaluation criteria and sample periods. The exchange rate equation implied by the interest rate rule that allows for interest rate and inflation inertia under commitment offers some encouraging results — exchange rate changes “calibrated” from the equation have a positive and significant correlation with actual data, and offer good direction of change prediction. Our exercise also demonstrates the role of the foreign exchange risk premium in determining exchange rates and the difficulty of explaining exchange rate variability using only policy based fundamentals.     

The Federal Home Loan Bank system: Cause or cure for disintermediation?

The Federal Home Loan Bank (FHLB) system issues bonds in order to obtain funds for savings and loan associations during periods of disintermediation. A question has arisen as to whether the FHLB actually causes additional disintermediation by its bond issues. Although this concern has been examined before statistically, with a connection found between FHLB borrowing and disintermediation, no explicit attention has been devoted to the possibility that such a statistical relationship may reflect a causality relationship in which disintermediation is the cause and FHLB borrowing the effect rather than the reverse. This study utilizes a simultaneous equation model and estimator to examine such two-way causality and finds it exists but that substantial disintermediation is caused by FHLB borrowing even after correcting for simultaneous equation bias.