Time-Varying Betas of German Stock Returns

The market model assumes stock returns to be a linear function of the market return. However, there is considerable evidence that the beta stability assumption commonly used when estimating the market model is invalid. In this paper we account for beta instability in German stock returns by allowing the coefficients to vary over time in estimation. For time-varying beta estimation we rely on the Flexible Least Squares approach, the Random Walk Model and Moving Window Least Squares. Due to our results time-varying estimation fits the data considerably better than time-invariant estimation and, hence, increases the efficiency of beta based risk measurement.Acknowledgements: The authors thank Stefan Mittnik, Christian Pigorsch, an anonymous referee and the editor for constructive comments.     

Idiosyncratic Risk,Investor Base,and Returns

Using four different proxies for a firm's investor base we demonstrate that idiosyncratic risk premiums are larger for neglected stocks and smaller or economically insignificant for visible stocks. Since neglected stocks have greater idiosyncratic volatility (IV), the total IV risk premium (price × quantity) for neglected stocks will be greater than that of visible stocks. Additionally, we find a positive size effect and negative beta effect after controlling for IV. Overall, our results provide strong support for Merton's theory that market segmentation induced by incomplete information is an important component of the influence of IV in the cross‐section of returns.     

Liquidity risk and arbitrage pricing theory

Classical theories of financial markets assume an infinitely liquid market and that all traders act as price takers. This theory is a good approximation for highly liquid stocks, although even there it does not apply well for large traders or for modelling transaction costs. We extend the classical approach by formulating a new model that takes into account illiquidities. Our approach hypothesizes a stochastic supply curve for a securitys price as a function of trade size. This leads to a new definition of a self-financing trading strategy, additional restrictions on hedging strategies, and some interesting mathematical issues.Received: 1 November 2003, Mathematics Subject Classification: 60G44, 60H05, 90A09JEL Classification: G11, G12, G13Umut Çetin: This work was performed while Dr. Çetin was at the Center for Applied Mathematics, Cornell UniversityPhilip Protter: Supported in part by NSF grant DMS-0202958 and NSA grant MDA-904-03-1-0092 The authors wish to thank M. Warachka and Kiseop Lee for helpful comments, as well as the anonymous referee and Associate Editor for numerous helpful suggestions, which have made this a much improved paper.     

Optimal Timing of Real Estate Investment under an Asymmetric Duopoly

This paper examines the sub-game equilibrium strategies for a duopoly real option model consisting of two firms with asymmetric demand functions. The relative strength of the firms is found to have significant impact on the firms’ equilibrium strategies. Preemptive strategies are critical if difference in strength between the two competing firms is relatively small. Short bursts and recession induced overbuilding are two outcomes in the asymmetric duopoly model. The model, however, predicts that the two phenomena occur in earlier phases of market cycles, rather than in the state of depression. In a depressed market with high volatility, the leader and the follower will both choose the waiting strategies. Construction cascade is, therefore, not an expected phenomenon in a depressed market in the asymmetric duopoly framework. Please forward your comments to the second author at rststf@nus.edu.sg. Your comments are appreciated. The authors wish to thank Stephen Cauley, Walter Torous, an anonymous referee, and participants in the Singapore–Hong Kong Real Estate Research Symposium on 14–15 July 2005 for their constructive comments and suggestions.     

Convergence of utility functions and convergence of optimal strategies

In this paper we study the stability (in the L ^p as well as for the almost sure convergence sense) of the optimal investment-consumption strategy with respect to the choice of the utility function.Received: February 2003, The authors want to thank an anonymous referee as well as an associate editor for their useful comments and suggestions (in particular, the development on the speed of convergence). The authors also thank R. A. Dana for helpful discussions and W. Schachermayer for careful reading.     

Value versus Growth: The International Evidence

Value stocks have higher returns than growth stocks in markets around the world. For the period 1975 through 1995, the difference between the average returns on global portfolios of high and low book-to-market stocks is 7.68 percent per year, and value stocks outperform growth stocks in twelve of thirteen major markets. An international capital asset pricing model cannot explain the value premium, but a two-factor model that includes a risk factor for relative distress captures the value premium in international returns.     

Understanding the Positive Announcement Effects of Private Equity Placements: New Insights from Hong Kong Data

The literature has documented positive announcement effects for privately placed seasoned equity issues. This study shows positive announcement effects not only for private but also for public placements in Hong Kong. Our unique data offer new insights not obtainable from U.S. data as we examine the cross-sections of the announcement effects. Most importantly, we find that the announcement effect is more likely to be positive for smaller issuers, such as private placing firms and some public issuers where asymmetric information arises more from growth than from assets in place. This finding is consistent with the generalized Myers-Majluf model.★The authors wish to thank Jack Cooney, Espen Eckbo, Ned Elton, Cliff Holderness, Rene Stulz, Piet Sercu, Tom Vinaimont, John Wei, and participants at the 2003 Financial Management Association Annual Conference in Denver and at seminars at the Guanghua School of Management of Peking University and the Department of Finance of National Taiwan University for their helpful discussions and comments. Special thanks go to Marco Pagano (the editor) and an anonymous referee for advice and suggestions that have significantly improved the quality of this paper. Wu gratefully acknowledges financial support from the Research Grants Council of the Hong Kong SAR (Project No. CityU 1244/04H) and from the City University of Hong Kong (DAG project No. 7100183).     

Three analyses of the firm size premium

The size premium for smaller companies is one of the best-known academic market anomalies. The relevant issue for investors is whether size premium for small-cap stocks is still positive, and, if so, whether its magnitude is substantial. In our analysis, we use annual compounded returns, monthly cross-sectional regressions, and linear spline regressions to investigate the relation between expected returns and firm size during 1980–1996. All three methodologies report no consistent relationship between size and realized returns. Hence, our results show that the widespread use of size in asset pricing is unwarranted.     

Empirical Evidence of the Existence of Investable Premiums in Emerging Market Investable Stocks

This paper shows that portfolios of more investable securities bear a premium when compared to portfolios of less investable stocks, reflecting compensation for local risk factors. The investable premium is overwhelmingly priced across 3,782 companies traded in 29 emerging markets from 1988 to 2006. The investable premium impacts stock returns at least as much as other fundamental premiums such as size, value, momentum, and loads on political, economic, and financial risk factors. The impact of the investable premium on emerging stocks returns has increased in strength, implying that foreign ownership has greater influence on local markets in recent years.     

Robust portfolio optimization with a generalized expected utility model under ambiguity

This paper proposes a robust approach maximizing worst-case utility when both the distributions underlying the uncertain vector of returns are exactly unknown and the estimates of the structure of returns are unreliable. We introduce concave convex utility function measuring the utility of investors under model uncertainty and uncertainty structure describing the moments of returns and all possible distributions and show that the robust portfolio optimization problem corresponding to the uncertainty structure can be reformulated as a parametric quadratic programming problem, enabling to obtain explicit formula solutions, an efficient frontier and equilibrium price system. We would like to thank Prof. Zengjing Chen from School of Mathematics and System Sciences, Shandong University for helpful suggestions, and to thank the anonymous referee for valuable comments.     

Habit formation,the cross section of stock returns and the cash-flow risk puzzle

Non-linear external habit persistence models, which feature prominently in the recent “equity premium” asset pricing and macroeconomics literature, generate counterfactual predictions in the cross-section of stock returns. In particular, we show that in the absence of cross-sectional heterogeneity in firms’ cash-flow risk, these models produce a “growth premium,” that is, stocks with high price-to-fundamental ratios command a higher premium than stocks with low price-to-fundamental ratios. This implication is at odds with the well-established empirical observation of a “value premium” in the cross-section of stock returns. Substantial heterogeneity in firms’ cash-flow risk yields both a value premium as well as most of the stylized facts about the cross-section of stock returns, but it generates a “cash-flow risk puzzle”: Quantitatively, value stocks have to have “too much” cash-flow risk compared to the data to generate empirically plausible value premiums.     

Do Invesrtors Capture the Value Premium?

Do investors realize higher returns by investing in value stocks instead of gorwth stocks? Examination of a sample of equity indexes, mutual funds, and large‐cap stocks reveals no evidence that value firms have earned higher returns than growth firms. The value premium reported in the literarture is historically strongest for small‐capitalization firms, yea average annual rerturns for small‐cap equity funds are 14.10% for value funds compared to 14.52% for growth funds. Despite dramatic increases in mutual fund expense ratios from 1965 to 2001, fee differences across style funds cannot explain the absence of a value premium.     

Interaction of size,book‐to‐market and momentum effects in Australia

This study seeks to disentangle the effects of size, book‐to‐market and momentum on returns. Initial results show that each characteristic has a role in explaining returns, but that there is interaction between size and momentum, as well as between size and book‐to‐market. Three key findings emerge. First, the size premium is the strongest, particularly in the loser portfolios. Second, the value premium is generally limited to the smallest portfolios. Third, the momentum premium is evident for the large‐ and middle‐sized portfolios, but loser stocks significantly outperform winner stocks in the smallest size portfolio. When these interactions are controlled with multivariate regression, we find a significant negative average relation between size and returns, a significant positive average relation between book‐to‐market and returns, and a significant positive average relation between momentum and returns.     

Accounting for the Accuracy of Beta Estimates in CAPM Tests on Assets with Time-varying Risks

This paper advocates two ways to make more efficient use of available information in reducing the bias of the risk premium estimate in two-pass tests of the CAPM. First, explicit modelling of the time-variability of betas can improve the accuracy of the beta forecasts. Second, the cross-sectional information available can be exploited more efficiently using individual stocks instead of portfolios provided that noisy beta predictions are given a smaller weight than more accurate ones. This paper proposes an adjustment of the cross-sectional regressions of excess returns against betas to give larger weights to more reliable beta forecasts. A significant positive relationship between returns and the beta forecast is obtained when the proposed approach is applied to data from the Helsinki Stock Exchange, while the traditional Fama–MacBeth approach as such finds no relationship at all.     

Illiquidity Premium in the MILA

This article analyzes the illiquidity premium in the MILA. Using seven proxies for illiquidity, we find a positive and significant illiquidity premium for our sample. A microstructure bias-free portfolio weighting based on past returns is critical in our finding of an illiquidity premium, which is robust to several methodological changes in our portfolio simulations. We also document that the premium is present only in small and high book-to-market stocks. Nonetheless, when we control for size and distress effects, the difference and significance in risk-adjusted returns between portfolios of high and low illiquidity stocks remains.     

The relation between stock returns and short-term interest rates

This study examines the relation between the expected returns on common stocks and short-term interest rates. Using a two-factor model of stock returns, we show that the expected returns on common stocks are systematically related to the market risk and the interest-rate risk, which are estimated as the sensitivity of common-stock excess returns to the excess return on the equally weighted market index and to the federal fund premium, respectively. We find that the interest-rate risk for small firms is a significant source of investors' portfolio risk, but is not properly reflected in the single-factor market risk. We also find that the interest-rate risk for large firms is “negative” in the sense that the market risk estimated from the single-factor model overstates the true risk of large firms. An application of the Fama-MacBeth methodology indicates that the interest-rate risk premium as well as the market's risk premium are significant, implying that both the market risk and the interest-rate risk are priced. We show that the interest-rate risk premium explains a significant portion of the difference in expected returns between the top quintile and the bottom quintile of the NYSE and AMEX firms. We also show that the turn-of-the-year seasonal is observed for the interest-rate risk premium; however, the risk premium for the rest of the year is still significant, although small in mangitude.     

Lender of last resort: A contemporary perspective

This article re-examines the role of the central bank's lender of last resort (LLR) function in the current economic environment. It argues that the traditional role of protecting the money supply from collapse is no longer valid. LLR intervention is appropriate to offset temporary liquidity strains that are likely to depress asset prices and aggregate real income below their equilibrium levels. However, such support should be provided only rarely and through open market operations rather than the discount window.This article was started while the author was visiting the Federal Reserve Bank of Dallas. The article was improved by constructive suggestions received from Douglas Evanoff, Gillian Garcia, Robert Laurent, Gerald O'Driscoll, Anna Schwartz, and an anonymous referee.