Christian C. P. Wolff

On the Biasedness of Forward Foreign Exchange Rates: Irrationality or Risk Premia?

In this article, the authors reconsider the K. A. Froot and J. A. Frankel (1989) results on the sources of forward discount bias. They question the economic validity of some estimation restrictions that they impose and, thus, are led to question some of their results. The authors employ a new exchange rate survey database that includes European Monetary System currencies and use univariate and pooling estimation techniques that impose fewer restrictions than those of Froot and Frankel to test their hypotheses. They find that the bias in the forward discount is attributable to both the failure of rational expectations and the existence of time-varying risk premia. Copyright 1994 by University of Chicago Press.

Contingent Capital: The Case of COERCs

This paper introduces, analyzes, and values a new form of contingent convertible (CoCo), a Call Option Enhanced Reverse Convertible (COERC). Issued as a bond, it converts to new shareholders’ equity if a bank’s market value of capital falls below a pre-specified trigger. The COERC avoids the problems with market based triggers such as “death spirals” as a result of manipulation or panic. A bank that issues COERCs also has a smaller incentive to choose investments that are subject to large losses. Furthermore, COERCs reduce the problem of “debt overhang,” the disincentive to replenish shareholders’ equity following a decline. The low risk of COERCS should increase their appeal to risk-averse bondholders.

The Dynamics of Short-Term Interest Rate Volatility Reconsidered

In this paper we present and estimate a model of short-term interest rate volatility that encompasses both the level effect of Chan, Karolyi, Longstaff and Sanders (1992) and the conditional heteroskedasticity effect of the GARCH class of models. This flexible specification allows different effects to dominate as the level of the interest rate varies. We also investigate implications for the pricing of bond options. Our findings indicate that the inclusion of a volatility effect reduces the estimate of the level effect, and has option implications that differ significantly from the Chan, Karolyi, Longstaff and Sanders (1992) model.

Foreign exchange rate expectations : survey and synthesis

This paper reviews the empirical literature on foreign exchange rate expectations. Prominent issues are the forward premium puzzle, expectations formation in financial markets, heterogeneity of expectations, market microstructure, time-varying risk premiums and forecast performance. Although much has been learned in each field, this survey highlights the areas of research in which our understanding of the mechanism of exchange rate expectations is still incomplete. Our survey suggests that both irrational expectations and time-varying risk premiums account for the forward discount anomaly, that long-term expectations reverse towards their long-run equilibrium values and that heterogeneous behaviour of market participants has the potential of explaining some of the empirical regularities in the international finance literature. Copyright 2007 The Authors. Journal compilation

Survey data and the interest rate sensitivity of US bank stock returns

In this paper, we provide empirical evidence on the interest rate sensitivity of the stock returns of the twenty largest US bank holding companies. The main contribution of the paper is the use of survey data to model the unexpected interest rate variable, which is an alternative approach to the existing literature. We find evidence of significant negative interest rate sensitivity during the early 1980s, and evidence of declining significance in the late 1980s and early 1990s. This result is also obtained when using the forecast errors of ARIMA processes to model the unexpected movement in the interest rate.

Premia in Forward Foreign Exchange as Unobserved Components: A Note

We reconsider the signal-extraction approach to measuring premia in the pricing of forward foreign exchange, put forward by Wolff, in which the difference between the forward rate and the associated future spot rate is modeled as an autoregressive moving average (ARMA) model for the risk premium buried in a white-noise forecast error. We point out that an ARMA model for the risk premium is not always identifiable from information on the difference between the forward rate and the future spot rate only. We present solutions to the problem of identification and show how the model for the risk premium can be estimated in a direct way, provided that the identification problem is solved. For reason of comparison, we use the series analyzed by Wolff to estimate the models for risk premia. The results confirm the earlier finding that premia in forward exchange exhibit a certain degree of persistence over time.

Loss Functions in Option Valuation: A Framework for Selection

In this paper, we investigate the importance of different loss functions when estimating and evaluating option pricing models. Our analysis shows that it is important to take into account parameter uncertainty, because this leads to uncertainty in the predicted option price. We illustrate the effect on the out-of-sample pricing errors in an application of the ad hoc Black-Scholes model to DAX index options. We confirm the empirical results of Christoffersen and Jacobs (Christoffersen, P., K. Jacobs. 2004. The importance of the loss function in option valuation. J. Financial Econom.72 291--318) and find strong evidence for their conjecture that the squared pricing error criterion may serve as a general-purpose loss function in option valuation applications. At the same time, we provide a first yardstick to evaluate the adequacy of the loss function. This is accomplished through a data-driven method to deliver not just a point estimate of the root mean squared pricing error, but a distribution.

Models of exchange rates: A comparison of forecasting results

Abstract In this note we compare the results of several published papers on exchange rate forecasting. With regard to univariate time series models, we confirm the result that such models, on average, do not outperform the simple random walk forecasting rule. This conclusion corrects results reported in this Journal by Alexander and Thomas (1987).

A Cumulative Prospect Theory Approach to Option Pricing

It is a well known empirical fact that actual option prices show persistent and systematic deviations from Black-Scholes option values. While a substantial number of enhancements have been proposed in the literature, these approaches typically leave investors’ preferences towards risk unmodified. In this paper we study option prices in an economy where investors are valuing call options according to the cumulative prospect theory of Kahneman and Tversky. We distinguish two prospect option pricing models, based on whether cash flows are either considered to be segregated or aggregated over time. These models are compared with the Black-Scholes model and the stochastic volatility model of Heston. Empirical analysis of European call options on the S&P 500 index shows that prospect option pricing models significantly improve the fitting performance compared with the Black-Scholes model and that especially the aggregated version’s performance is at least equivalent to the Heston model.

Forward foreign exchange rates and expected future spot rates

This paper explores whether knowledge of the time-series properties of the premium in the pricing of forward foreign exchange can be usefully exploited in forecasting future spot exchange rates. Signal-extraction techniques, based on recursive application of the Kalman filter, are used to measure the premium. Predictions using premium models compare favourably with those obtained from the use of the forward rate as a predictor of the future spot rate. The results also provide an interesting description of the time-series properties of the premium