金融监管信号传递与金融市场有效运行

金融市场是金融监管当局与金融市场参与者之间动态博弈、合作共生的信息不对称系统。通过把信号博弈和重复博弈思想引入金融监管理论研究,构建以金融市场有效运行为反馈信号的金融监管当局与金融市场参与者之间的监管信号传递模型,分析金融市场治理中有效监管信号的传递机制。结果表明：金融监管力度与金融市场有效运行水平之间存在分离、混同两种均衡关系;在金融监管声誉效应的驱动下,金融监管当局倾向于选择混同均衡策略,而不是分离均衡。因而只有建立通畅的金融监管信号传递及反馈机制,强化并放大金融监管信号显示,增大监管乘数效应,形成良性的监管声誉效应,才能保障金融市场的有效运行。     

Information provision in financial markets

We set up a rational expectations model in which investors trade a risky asset based on a private signal they receive about the quality of the asset, and a public signal that represents a noisy aggregation of the private signals of all investors. Our model allows us to examine what happens to market performance (market depth, price efficiency, volume of trade, and expected welfare) when regulators can induce improved information provision in one of two ways. Regulations can be designed that either provide investors with more accurate information by improving the quality of prior information, or that enhance the transparency of the market by improving the quality of the public signal. In our rational expectations equilibrium, improving the quality of the public signal can be interpreted as a way of providing information about the anticipations and trading motives of all market participants. We find that both alternatives improve market depth. However, in the limit, we show that improving the precision of prior information is a more efficient way to do so. More accurate prior information decreases asymmetric information problems and consequently reduces the informativeness of prices, while a more accurate public signal increases price informativeness. The volume of trade is independent of the quality of prior information and is increasing in the quality of the public signal. Finally, expected welfare can sometimes fall as prior information or the public signal become more precise.     

Signaling-Screening Equilibrium in the Mortgage Market

The signaling model of Spence (1973a) and the screening model of Rothchild and Stiglitz (1976) have been separately used to explain economic phenomena when there is asymmetric information. In the real world, however, situations of asymmetric information often simultaneously involve signaling and screening. In this paper, we combine signaling and screening mechanisms and demonstrate a signaling-screening separating equilibrium. We present the analysis within the framework of mortgage markets. Borrowers signal their default risk types to lenders by acquiring different credit records. This partially separates borrowers into subsets. Lenders screen each subset by offering menus of mortgage loan contracts. Borrowers, then, self-select by choosing particular contracts from the menu. We show the conditions under which the signaling-screening equilibrium is Pareto superior to a screening-only equilibrium.     

The Downside of Asset Screening for Market Liquidity

This paper explores the tension between asset quality and market liquidity. I model an originator who screens assets whose cash flows are later sold in secondary markets. Screening improves asset quality but gives rise to asymmetric information, hindering trade of the asset cash flows. In the optimal mechanism (second‐best), costly retention of cash flows is essential to implement asset screening. Market allocations can feature too much or too little screening relative to second‐best, where too much screening generates inefficiently illiquid markets. Furthermore, the economy is prone to multiple equilibria. The optimal mechanism is decentralized with two tools: retention rules and transfers.     

Dividend policy under conditions of capital market and signaling equilibria

This article develops a generalized capital asset pricing model with dividend signaling under the assumption of asymmetric information between corporate insiders and outside investors. The generalized capital asset pricing model is derived under reasonably plausible conditions that are sufficient for the existence of dividends. The model provides a theoretical framework for testing the effect of dividends on equity price and returns. Further, if dividends serve as a credible signal and the cost of signaling is positive, paying higher dividends results in higher systematic risk.     

Government as borrower of first resort

Optimal government bond supply is examined under asymmetric information and safe asset scarcity. Corporations issue junk debt when demand for safe debt is high since uninformed investors then migrate to risky overheated debt markets. Uninformed demand stimulates informed speculation, driving debt prices toward fundamentals, encouraging pooling at high leverage. As borrower of first resort, government can issue bonds, siphoning off uninformed demand for risky corporate debt, reducing wasteful informed speculation. Government bonds eliminate pooling at high leverage or improve risk sharing in such equilibria. Optimal government bond supply is increasing in demand for safe assets and non-monotonic in marginal Q.     

The issuance of callable bonds under information asymmetry

We reconsider the role of asymmetric information in motivating the issuance of callable bonds. The previous literature has emphasized a possibility that a call feature serves as a signal of issuer quality. We demonstrate that asymmetric information can motivate use of a call even when this action does not signal quality in equilibrium. We construct a matched sample of callable and non-callable bonds that permits us to control for non-informational effects on the call issuance decision. Empirical evidence from speculative grade bond markets is consistent with the hypotheses that asymmetric information motivates use of the call feature, but there is no evidence that inclusion of the call functions as a signal to the market.     

Asset Measurement in Imperfect Credit Markets

How should a firm measure a productive asset used as collateral? To answer this question, we develop a model in which firms borrow funds subject to collateral constraints. We characterize the qualities of optimal asset measurements and analyze their interactions with financing needs, collateral constraints, and interest rates. Because of real effects, complete transparency would reduce contracting efficiency and, hence, the measurement must be suitably adapted to credit conditions. The optimal measurement is asymmetric and reports precise information about high collateral values if credit frictions are low, but the reverse if credit frictions are high. Tighter credit market conditions may lead to more opaque measurements and increased investment, in the form of inefficient continuations.     

Partial Revelation of Information in Experimental Asset Markets

We develop a model of market efficiency assuming private information is partially revealed to uninformed traders via the behavior of those who are informed. This partial revelation of information (PRE) model is tested in fourteen computerized double auction laboratory markets. It explains the market value and allocation of purchased information, and asset allocations, better than either a fully revealing information model (FRE strong-form efficiency) or a nonrevealing expectations model; but it takes second place to FRE in explaining asset prices. We conjecture that refined versions of PRE may provide insight into “technical analysis” and minibubbles in securities markets.     

Using implied volatility on options to measure the relation between asset returns and variability

Prior research has documented that volatility in financial asset markets is most directly related to trading rather than calendar days, and that there is an inverse asymmetric relation between volatility and returns in both stocks and long-term bonds. We examine these relations in 37 futures options markets representing a wide variety of asset types. Using futures prices and implied volatilities from this extensive array of markets, we confirm that in all of them, save one, market volatility is more directly related to trading days. However, the nature of the association between implied volatility and underlying asset returns varies greatly across asset categories and across exchanges. Thus, we show that findings from equity markets apparently are not generalizable to other asset classes.     

News‐Specific Price Discovery in Credit Default Swap Markets

We examine the lead and lag relation between equity and credit default swap (CDS) markets. We find that price discovery in equity markets only leads CDS markets following aggregate positive news and not so following other news. While difficult to reconcile with standard asset pricing theories, asymmetric price adjustment is common in goods markets, arising from intermediary power. We provide an explanation for this asymmetry based on dealers exploiting informational advantages vis‐à‐vis investors with hedging motives. Consistent with this explanation, we find that the patterns we document are related to firm‐level proxies for hedging demand, as well as economy‐wide measures of information asymmetries.     

Cream Skimming, Dregs Skimming, and Pooling: On the Dynamics of Competitive Screening

We discuss the existence of a pooling equilibrium in a two-period model of an insurance market with asymmetric information. We solve the model numerically. We pay particular attention to the reasons for non-existence in cases where no pooling equilibrium exists. In addition to the phenomenon of cream skimming emphasized in earlier literature, we here point to the importance of the opposite: dregs skimming, whereby high-risk consumers are profitably detracted from the candidate pooling contract.     

Herding behavior in asset markets

This paper examines the origins of herding behavior in asset markets and its potential to produce a price bubble. I present a model which explains the emergence and the development of herding behavior via asymmetric information and Baysian learning. A corresponding price bubble is explained through herding behavior without assuming any speculative incentives on the part of the investors.     

The Impact of Search Costs and Asymmetric Information on Current Value Accounting

This paper examines the impact that search costs and asymmetric information would have on financial statements if either of the two main systems of current value accounting were introduced. The significance of search costs is that, although the models which determine the optimal amount of search are becoming more general, they are based on very restrictive assumptions and are of limited practical application. In relation to the second issue, where asset markets are dominated by asymmetric information, the ‘signal’ conveyed by the accounts would be misleading. It is argued that, whilst these two issues can more easily be resolved where the provision of financial information is unregulated, they are likely to be important considerations in the political process which results in an accounting standard.     

Presidential Address: Liquidity and Price Discovery

This paper examines the implications of market microstructure for asset pricing. I argue that asset pricing ignores the central fact that asset prices evolve in markets. Markets provide liquidity and price discovery, and I argue that asset pricing models need to be recast in broader terms to incorporate the transactions costs of liquidity and the risks of price discovery. I argue that symmetric information‐based asset pricing models do not work because they assume that the underlying problems of liquidity and price discovery have been solved. I develop an asymmetric information asset pricing model that incorporates these effects.     

Explaining share price disparity with parameter uncertainty: Evidence from Chinese A- and H-shares

The price disparity between the A- and H-share markets for dual-listed firms in China is one of the most intriguing puzzles in the Mainland and Hong Kong financial markets. In this paper, we revisit this price disparity puzzle using the channel of parameter uncertainty. In the presence of information asymmetry and market segmentation, investors have different views on a firm’s asset volatility, and hence different valuations of the same reference firm. We estimate a structural model for equity pricing using a Bayesian approach, in which the uncertainty of investor model parameters is represented by the posterior standard deviation of the firm’s asset volatility. Our regression analysis shows that in addition to other market-based and macro factors, parameter uncertainty explains variations in price disparity.     

Limited disclosure and hidden orders in asset markets

Opacity assumes at least two prominent forms in asset markets. Dark exchanges and over-the-counter markets enable expert investors to hide their orders while originators carefully control the disclosure of fundamental information about the assets they source. We describe a simple model in which both forms of opacity – hidden orders and limited disclosure – complement one another. Costly investor expertise gives originators incentives to deliver assets of good quality. Keeping expert orders hidden generates the rents investors need to justify investing in expertise in the first place. Limiting disclosure mitigates the resulting adverse selection issues. Originators prefer to restrict the information they can convey to experts because it encourages the participation of non experts. This optimal organization of asset markets can be decentralized using standard financial arrangements.     

Option Volume and Stock Prices: Evidence on Where Informed Traders Trade

This paper investigates the informational role of transactions volume in options markets. We develop an asymmetric information model in which informed traders may trade in option or equity markets. We show conditions under which informed traders trade options, and we investigate the implications of this for the linkage between markets. Our model predicts an important informational role for the volume of particular types of option trades. We empirically test our model's hypotheses with intraday option data. Our main empirical result is that negative and positive option volumes contain information about future stock prices.     

Modeling the cross-section of stock returns using sensible models in a model pool

An increase in the number of asset pricing models intensifies model uncertainties in asset pricing. While a pure “model selection” (singling out a best model) can result in a loss of useful information, a full “model pooling” may increase the risk of including noisy information. We make a trade-off between the two methods and develop a new two-step trimming-then-pooling method to forecast the joint distributions of asset returns using a large pool of asset pricing models. Our method allows investors to focus on certain regions of the distributions. In the first step, we trim the uninformative models from a pool of candidates, and in the second step, we pool the forecasts of the surviving models. We find that our method significantly enhances portfolio performance and predicts downside risk precisely, and the improvements are mainly due to trimming. The pool of sensible models becomes larger when focusing on extreme events, responds rapidly to rising uncertainty, and reflects the magnitude of factor premiums. These findings provide new insights into asset pricing model evaluation.     

The performance of model based option trading strategies

This paper analyzes returns to trading strategies in options markets that exploit information given by a theoretical asset pricing model. We examine trading strategies in which a positive portfolio weight is assigned to assets which market prices exceed the price of a theoretical asset pricing model. We investigate portfolio rules which mimic standard mean-variance analysis is used to construct optimal model based portfolio weights. In essence, these portfolio rules allow estimation risk, as well as price risk to be approximately hedged. An empirical exercise shows that the portfolio rules give out-of-sample Sharpe ratios exceeding unity for S&P 500 options. Portfolio returns have no discernible correlation with systematic risk factors, which is troubling for traditional risk based asset pricing explanations.