Is the bond market irrational?

Bond market

High equity premia and crash fears. Rational foundations

We show that when in Lucas trees model the process for dividends is described by a lattice tree subject to infrequent but observable structural breaks, in equilibrium recursive rational learning may inflate the equity risk premium and reduce the risk-free interest rate for low levels of risk aversion. The key condition for these results to obtain is the presence of sufficient initial pessimism. The relevance of these findings is magnified by the fact that under full information our artificial economy cannot generate asset returns matching the empirical evidence for any positive relative risk aversion.Assets (Accounting) ; Rational expectations (Economic theory)

Pessimistic beliefs under rational learning: quantitative implications for the equity premium puzzle

In the presence of infrequent but observable structural breaks, we show that a model in which the representative agent is on a rational learning path concerning the real consumption growth process can generate high equity premia and low risk-free interest rates. In fact, when the model is calibrated to U.S. consumption growth data, average risk premia and bond yields similar to those displayed by post- depression (1938-1999) U.S. historical experience are generated for low levels of risk aversion. Even ruling out pessimistic beliefs, recursive learning inflates the equity premium without requiring a strong curvature of the utility function. Simulations reveal that other moments of equilibrium asset returns are easily matched, chiefly excess volatility and the presence of ARCH effects. These findings are robust to a number of details of the simulation experiments, such as the number and dating of the breaks.Assets (Accounting) ; Rational expectations (Economic theory)

The dollar U-turn

Dollar, American

Managing international portfolios with small capitalization stocks

In the context of an international portfolio diversification problem, we find that small capitalization equity portfolios become riskier in bear markets, i.e. display negative co-skewness with other stock indices and high co-kurtosis. Because of this feature, a power utility investor ought to hold a well-diversified portfolio, despite the high risk premium and Sharpe ratios offered by small capitalization stocks. On the contrary small caps command large optimal weights when the investor ignores variance risk, by incorrectly assuming joint normality of returns. The dominant factor in inducing such shifts in optimal weights is represented by the co-skewness, the predictable, time-varying covariance between returns and volatilities. We calculate that if an investor were to ignore co-skewness and co-kurtosis risk, he would suffer a certainty-equivalent reduction in utility equal to 300 basis points per year under the steady-state distribution for returns. Our results are qualitatively robust when both European and North American small caps are introduced in the analysis. Therefore this paper offers robust evidence that predictable covariances between means and variances of stock returns may have a first order effect on portfolio composition.Investments, Foreign ; Stocks

What tames the Celtic tiger? portfolio implications from a multivariate Markov switching model

We use multivariate regime switching vector autoregressive models to characterize the time-varying linkages among the Irish stock market, one of the top world performers of the 1990s, and the US and UK stock markets. We find that two regimes, characterized as bear and bull states, are required to characterize the dynamics of excess equity returns both at the univariate and multivariate level. This implies that the regimes driving the small open economy stock market are largely synchronous with those typical of the major markets. However, despite the existence of a persistent bull state in which the correlations among Irish and UK and US excess returns are low, we find that state comovements involving the three markets are so relevant to reduce the optimal mean variance weight carried by ISEQ stocks to at most one-quarter of the overall equity portfolio. We compute time-varying Sharpe ratios and recursive mean-variance portfolio weights and document that a regime switching framework produces out-of-sample portfolio performance that outperforms simpler models that ignore regimes. These results appear robust to endogenizing the effects of dynamics in spot exchange rates on excess stock returns.Stock exchanges

Modelling the MIB30 implied volatility surface. Does market efficiency matter?

We analyze the volatility surface vs. moneyness and time to expiration implied by MIBO options written on the MIB30, the most important Italian stock index. We specify and fit a number of models of the implied volatility surface and find that it has a rich and interesting structure that strongly departs from a constant volatility, Black-Scholes benchmark. This result is robust to alternative econometric approaches, including generalized least squares approaches that take into account both the panel structure of the data and the likely presence of heteroskedasticity and serial correlation in the random disturbances. Finally we show that the degree of pricing efficiency of this options market can strongly condition the results of the econometric analysis and therefore our understanding of the pricing mechanism underlying observed MIBO option prices. Applications to value-at-risk and portfolio choice calculations illustrate the importance of using arbitrage-free data only.Assets (Accounting) ; Prices

Economic Implications of Bull and Bear Regimes in UK Stock Returns

This paper presents evidence of persistent `bull' and `bear' regimes in UK stock returns and considers their economic implications from the perspective of an investor's portfolio decisions. We find that the perceived state probability has a large effect on the optimal allocation to stocks, particularly at short investment horizons. If ignored, the presence of such regimes gives rise to welfare costs that are substantial, particularly in the bear state where stock holdings should be significantly reduced. When we extend the return forecasting model to allow for predictability from the lagged dividend yield, we find that both dividend yields and regime switching have strong effects on the optimal asset allocation.optimal asset allocation, regime switching, Bull and Bear Markets, model specification

Optimal portfolio choice under regime switching, skew and kurtosis preferences

This paper proposes a new tractable approach to solving multi-period asset allocation problems. We assume that investor preferences are defined over moments of the terminal wealth distribution such as its skew and kurtosis. Time-variations in investment opportunities are driven by a regime switching process that can capture bull and bear states. We develop analytical methods that only require solving a small set of difference equations and thus are very convenient to use. These methods are applied to a simple portfolio selection problem involving choosing between a stock index and a risk-free asset in the presence of bull and bear states in the return distribution. If the market is in a bear state, investors increase allocations to stocks the longer their time horizon. Conversely, in bull markets it is optimal for investors to decrease allocations to stocks the longer their investment horizon.Assets (Accounting)

Ambiguity in asset pricing and portfolio choice: a review of the literature

A growing body of empirical evidence suggests that investors’ behavior is not well described by the traditional paradigm of (subjective) expected utility maximization under rational expectations. A literature has arisen that models agents whose choices are consistent with models that are less restrictive than the standard subjective expected utility framework. In this paper we conduct a survey of the existing literature that has explored the implications of decision-making under ambiguity for financial market outcomes, such as portfolio choice and equilibrium asset prices. We conclude that the ambiguity literature has led to a number of significant advances in our ability to rationalize empirical features of asset returns and portfolio decisions, such as the empirical failure of the two-fund separation theorem in portfolio decisions, the modest exposure to risky securities observed for a majority of investors, the home equity preference in international portfolio diversification, the excess volatility of asset returns, the equity premium and the risk-free rate puzzles, and the occurrence of trading break-downs.Capital assets pricing model ; Investments