Stock market dynamics with rational liquidity traders

In the Kyle (1985) finite horizon model of stock market dynamics with a trader who holds long-lived information, informed trading intensities rise with time, and the slopes of the equilibrium price schedules fall. This paper shows that this result depends crucially on the irrational liquidity trader assumption. We replace the irrational noise traders with a sequence of rational, risk averse, liquidity traders who receive endowment shocks to their holdings of the risky asset. We demonstrate that unless liquidity traders are sufficiently risk averse, the slope of equilibrium price schedule rises over time, while informed trading intensities fall. In particular, Kyle's result holds only when liquidity traders are so risk averse that they ‘over-rebalance’ their portfolio's holdings of the risky asset, so that their final holdings of the risky asset have the opposite sign of their initial position.     

Dynamic price discovery

This article analyzes the dynamic process of price discovery in a competitive securities market where investors are equally informed about the fundamental determinants of an asset's end-of-period value but, because they do not know each other's wealth positions, do not know the equilibrium price of shares at the start of a current trading session. Because a large number of participants is assumed, issues concerning market impact and market manipulation are avoided. As trading progresses, participants update their expectations of an asset's equilibrium value. As they do so, price can either converge to a new level or, following a run, revert back to a previous level. This implies that, in clusters of adjacent prices, price changes are more apt to be predominantly of like sign (positive or negative) than would be the case under random walk with a bid-ask spread. Moreover, reversals, when they do occur, should be larger than continuations. An examination of 1988 transactions data for the 30 Dow Jones Industrial stocks shows that this is indeed the case. With the effect of the bid-ask spread removed, first-order autocorrelation coefficients are found to be positive.     

Margin requirements and stock volatility

Since 1934 the Federal Reserve Board has had the power to set separate limits on the amount of credit that can be extended to purchasers of common stock. There has been much recent debate about the efficacy of these margin regulations. This article argues that the Fed has responded to increases in stock prices by raising margin requirements. The increase in prices has been associated with a decrease in volatility. There is no evidence that changes in margin requirements reduce subsequent stock return volatility. Also, trading halts have not had much effect on volatility in the past. Trading halts that were associated with banking panics were associated with high stock return volatility, but halts without bank panics were not associated with high levels of volatility.This article summarizes discussion that was presented at the Columbia Center for the Study of Futures Markets Conference on Regulatory Reform of Stock and Futures Markets, May 12, 1989.     

Ambiguous Information,Portfolio Inertia,and Excess Volatility

I study the effects of risk and ambiguity (Knightian uncertainty) on optimal portfolios and equilibrium asset prices when investors receive information that is difficult to link to fundamentals. I show that the desire of investors to hedge ambiguity leads to portfolio inertia and excess volatility. Specifically, when news is surprising, investors may not react to price changes even if there are no transaction costs or other market frictions. Moreover, I show that small shocks to cash flow news, asset betas, or market risk premia may lead to drastic changes in the stock price and hence to excess volatility.     

Price volatility,welfare, and trading hours in asset markets

This paper studies the consequences of opening asset markets more often for the properties of asset prices and social welfare. For all reasonable parameter values, increasing trading hours lowers average asset prices, increases unconditional asset price volatility at a given point in time, and decreases unconditional asset price volatility when averaged over the period of time that includes the additional hours that markets are open. Unconditional social welfare is increased by opening markets more often, although the welfare gains are small – well below 1% of lifetime consumption. In contrast, because expanding hours of trading affects agents' information sets, the welfare effect of more trading hours conditional on information available to agents can be large and the effect can be negative.     

Valuation of risky assets in arbitrage-free economies with transactions costs

This paper analyzes the equilibrium valuation of risky assets in the case where transactions costs are present. The methodology involves applying ‘theorems of the alternative’ (Farkas' Lemma) as a consequence of arbitrage-free markets. Under relevant assumptions, it is found that the price of an asset having transactions costs is the corresponding price that would obtain in a perfect market, plus a ‘fudge factor’. This latter factor is provided explicit bounds.     

Trading Behavior and the Unbiasedness of the Market Reaction to Dividend Announcements

This article examines the price formation process during dividend announcement day, using daily closing prices and transactions data. We find that the unconditional positive excess returns, first documented by Kalay and Loewenstein (1985) , are higher for small-firm and low-priced stocks. Price volatility and trading volume also increase during this period. Examination of trade prices relative to the bid-ask spread and volume of trades at bid and asked prices shows that the excess returns cannot be attributed to measurement errors or to spillover effects of tax-related ex-day trading. Rather, the price behavior is related to the absorption of dividend information.     

Asymmetric-information and principal-agent problems as sources of value in FSLIC-Assisted acquisitions of insolvent thrifts

This study uses a two-factor market-model to estimate excess returns around 43 announcements of FSLIC-assisted thrift mergers and 66 announcements of unassisted thrift mergers. These estimated excess returns are then used to test hypotheses about asymetric-information and principal-agent problem in the thrift resolution process as sources of value in these mergers. The results show that acquirers in assisted transactions earned positive and statistically significant excess returns of approximately 2 percent, whereas acquirers in unassisted transactions earned excess returns that are not significantly different from zero; however, the excess returns in the assisted mergers are quantitatively small. For the 43 assisted mergers, estimated excess returns imply aggregate wealth transfers of only $13 million as compared with $2.3 billion in FSLIC assistance that were granted in these transactions. These findings suggest that the FSLIC-assisted transactions were reasonably well structured and that the assistance granted did not result in large wealth transfers to acquirers of insolvent institutions. Finally, the study provides evidence that informational asymmetries and principal-agent problems in the thrift resolution process were significant sources of excess returns for the acquirers receiving FSLIC assistance.The views reflected in this paper are those of the authors and do not necessarily represent policies of Board of Governors of the Federal Reserve System or the Federal Housing Finance Board. Helpful comments were recieved from participants in the Finance Workshop at the University of North Carolina at Chapel Hill, George Benston, Richard Brown, Jennifer Conrad, Sally Davies, Mark Flannery, Edward Kane, David Ravenscraft, and Lawrence J. White.     

REGIME CHANGES IN STOCK RETURNS

This paper studies three sources of instability in parameter estimates of stock return models (1) time-varying expected mean returns, (2) time-varying return volatility and (3) changing institutional factors. We model United States stock returns as a function of a constant expected return and financing costs resulting from an institutional feature, delayed delivery. We examine two eight-year periods and find that both contain a regime shift driven by an abrupt change in volatility. The first occurs during an international monetary crisis amid important Watergate developments. The second is on the first trading day after the reappointment of Paul Volcker as the chairman of the United States Federal Reserve Board.     

Competition,premature trading and excess volatility

A substantial body of research suggests that it is difficult to account for all of the volatility of asset prices in terms of news. This paper attempts to explain the excess volatility puzzle as a consequence of competitive interaction between market participants in the presence of noisy information. We develop a model of competitive interaction between market participants in response to unverified information. Our model shows that in the presence of competitive pressures, market participants find it optimal to act prematurely on unverified information. This premature reaction leads to lower total profits and excess market volatility in equilibrium. Our model also shows that the spike in volatility at the closing time of the market can be modelled as a direct consequence of premature trading.     

Stock market volatility and equity returns: Evidence from a two-state Markov-switching model with regressors

This paper proposes a two-state Markov-switching model for stock market returns in which the state-dependent expected returns, their variance and associated regime-switching dynamics are allowed to respond to market information. More specifically, we apply this model to examine the explanatory and predictive power of price range and trading volume for return volatility. Our findings indicate that a negative relation between equity market returns and volatility prevails even after having controlled for the time-varying determinants of conditional volatility within each regime. We also find an asymmetry in the effect of price range on intra- and inter-regime return volatility. While price range has a stronger effect in the high volatility state, it appears to significantly affect only the transition probabilities when the stock market is in the low volatility state but not in the high volatility state. Finally, we provide evidence consistent with the ‘rebound’ model of asset returns proposed by Samuelson (1991), suggesting that long-horizon investors are expected to invest more in risky assets than short-horizon investors.     

Behavioral asset pricing under expected feedback mode

We develop an enhanced DSSW model of behavior asset pricing by introducing the expected feedback mode. Through numerical simulation, it has been theoretically proved that risky asset price is jointly determined by trend extrapolated effect of expected feedback traders and the creating space effect of noise traders, and that price fluctuation depends on the expected feedback coefficient. As expected feedback traders' expectation return has been realized and the above two effects are obviously imbalance, their confidence will deteriorate prior to price collapse, and eventually achieve self-fulfilling expectation of price reversal in the process of price momentum. This model sheds lights on financial anomalies of trade size clustering and the formation of stock bubble, besides it provides a new perspective for avoiding the “bewitching” trading and reducing market volatility.     

Margin requirements and equilibrium asset prices

This paper studies the effect of margin requirements on asset prices and trading volume in a general equilibrium asset pricing model where Epstein-Zin investors differ in their degree of risk aversion. Under the assumptions of unit intertemporal elasticity of substitution and zero net supply of riskless assets, I show analytically that binding margin requirements do not affect stock prices. This result stands in contrast to previous partial equilibrium analysis where fixed margin requirements increase the volatility of stock prices. In this framework, binding margin requirements induce a fall in the riskless rate, increase its volatility, and increase stock trading volume.     

Discount rate changes,stock market returns,volatility, and trading volume: Evidence from intraday data and implications for market efficiency

We examine the effect of discount rate changes on stock market returns, volatility, and trading volume using intraday data. Equity returns generally respond negatively and significantly to the unexpected announcements; however, the effect of expected changes on equity returns is insignificant. Furthermore, our results indicate that equity prices respond to announcements within the trading period/hour after the information release. An indication of a return reversal is too small to cover the full transaction costs. Unexpected discount rate changes also contribute to higher market volatility although the volatility is short-lived. Similarly, unexpected changes in discount rates induce larger trading volume while expected changes do not. Abnormal trading volume occurs only in period t. Our results also support the notion that unexpected changes in the discount rates impact market returns irrespective of the Federal Reserve operating procedures.     

Price formation on stock exchanges: the evolution of trading within the day

Prior analyses of prices of the NYSE and other exchanges findthat transitory price volatility is greater at the open of tradingthan at the close. We extend this line of research by using40 years of hourly Dow Jones 65 composite price index data toestimate transitory volatility throughout the trading day. Ourresults indicate that transitory volatility steadily declinesduring the trading day. We find a similar intraday decline intransitory volatility for a 2-year sample of the individualfirms in the Dow Jones 30 Industrials Index. The results areconsistent with the hypothesis that trading aids price formationand do not support the argument that particular trading mechanismsare the source of greater volatility at the open of trading.     

Liquidity in Frictional Asset Markets

On November 14–15, 2008, the Federal Reserve Bank of Cleveland hosted a conference on “Liquidity in frictional asset markets.” In this paper, we review the literature on asset markets with trading frictions in both finance and monetary theory using a simple search‐theoretic model, and we discuss the papers presented at the conference in the context of this literature. We will show the diversity of topics covered in this literature, for example, the dynamics of housing and credit markets, the functioning of payment systems, optimal monetary policy and the cost of inflation, the role of banks, the effect of informational frictions on asset trading.     

The impact of transaction duration,volume and direction on price dynamics and volatility

We explore the role of trade volume, trade direction, and the duration between trades in explaining price dynamics and volatility using an Asymmetric Autoregressive Conditional Duration model applied to intraday transactions data. Our results suggest that volume, direction and duration are important determinants of price dynamics, while duration is also an important determinant of volatility. However, the impact of volume and direction on volatility is marginal after controlling for duration, and the impact of volume on volatility appears to be confined to periods of infrequent trading.     

Analyzing Federal Reserve asset purchases: From whom does the Fed buy?

Asset purchases have become an important monetary policy tool of the Federal Reserve in recent years. To date, most studies of the Federal Reserve’s asset purchases have tried to measure the interest rate effects of the purchases, and several provide evidence that these purchases do have important effects on longer-term market interest rates. The theory of how asset purchases work, however, is less well developed. Some of the empirical studies point to “preferred habitat” models in which investors do not have the same objectives, and therefore prefer to hold different types and maturities of securities. To study this more closely, we exploit Flow of Funds data to assess the types of investors that are selling to the Federal Reserve and their portfolio adjustment after these sales, which could provide a view to the plausibility of preferred habitat models and the transmission of unconventional monetary policy across asset markets. We find that the Federal Reserve is ultimately buying from only a handful of investor types, primarily households (which includes hedge funds), with a different reaction to changes in Federal Reserve holdings of longer-term versus shorter-term assets. Although not evident for all investors, the key participants are shown to rebalance their portfolios toward more risky assets during this period. These results can be interpreted as supporting, at least in part, the preferred habit theory and the view that the monetary policy transmission is working across asset markets.     

On the Inverse of the Covariance Matrix in Portfolio Analysis

The goal of this paper is the derivation and application of a direct characterization of the inverse of the covariance matrix central to portfolio analysis. Such a characterization, in terms of a few primitive constructs, provides the basis for new and illuminating expressions for key concepts as the optimal holding of a given risky asset and the slope of the risk-return efficiency frontier faced by the individual investor. The building blocks of the inverse turn out to be the regression coefficients and residual variance obtained by regressing the asset's excess return on the set of excess returns for all other risky assets.     

再析美国金融危机前的利率政策

全球金融危机与美国货币政策的变化密不可分,从低利率货币信贷扩张的流动性过剩到高利率的流动性紧缩,使宏观经济产生剧烈波动,前期低利率带来过剩的流动性,后期利率的提高造成巨量房地产泡沫的破灭。让美联储无视资产泡沫的原因是美联储货币政策一贯秉持的"泰勒规则"指导原则没有纳入资产价格因子,致使美联储货币政策调控失误。