Finite Dimensional Affine Realisations of HJM Models in Terms of Forward Rates and Yields

Finite dimensional Markovian HJM term structure models provide ideal settings for the study of term structure dynamics and interest rate derivatives where the flexibility of the HJM framework and the tractability of Markovian models coexist. Consequently, these models became the focus of a series of papers including Carverhill (1994), Ritchken and Sankarasubramanian (1995), Bhar and Chiarella (1997), Inui and Kijima (1998), de Jong and Santa-Clara (1999), Björk and Svensson (2001) and Chiarella and Kwon (2001a). However, these models usually required the introduction of a large number of state variables which, at first sight, did not appear to have clear links to the market observed quantities, and the explicit realisations of the forward rate curve in terms of the state variables were unclear. In this paper, it is shown that the forward rate curves for these models are affine functions of the state variables, and conversely that the state variables in these models can be expressed as affine functions of a finite number of forward rates or yields. This property is useful, for example, in the estimation of model parameters. The paper also provides explicit formulae for the bond prices in terms of the state variables that generalise the formulae given in Inui and Kijima (1998), and applies the framework to obtain affine representations for a number of popular interest rate models.     

Author Index of Volume 8 2001

Authors Index

Author Index of Volume 8 2001     

The cournot-nash and cooperative solutions in the harvesting of a fish stock

The questions of optimal extinction and of market imperfections in the harvesting of a fish stock is analyzed using two different objective functions, one discounted utility of fish consumption and the other discounted profit, both over an infinite horizon.     

Evaluation of American option prices in a path integral framework using Fourier–Hermite series expansions

In this paper we review the path integral technique which has wide applications in statistical physics and relate it to the backward recursion technique which is widely used for the evaluation of derivative securities. We formulate the pricing of equity options, both European and American, using the path integral framework. Discretising in the time variable and using expansions in Fourier–Hermite series for the continuous representation of the underlying asset price, we show how these options can be evaluated in the path integral framework. For American options, the solution technique facilitates the accurate determination of the early exercise boundary as part of the solution. Additionally, the continuous representation of the state variable allows the relatively accurate and efficient evaluation of the option prices and the delta hedge ratio.     

A behavioural model of investor sentiment in limit order markets

By incorporating behavioural sentiment in a model of a limit order market, we show that behavioural sentiment not only helps to replicate most of the stylized facts in limit order markets simultaneously, but it also plays a unique role in explaining those stylized facts that cannot be explained by noise trading, such as fat tails in the return distribution, long memory in the trading volume, an increasing and non-linear relationship between trade imbalance and mid-price returns, as well as the diagonal effect, or event clustering, in order submission types. The results show that behavioural sentiment is an important driving force behind many of the well-documented stylized facts in limit order markets.     

The representation of American options prices under stochastic volatility and jump-diffusion dynamics

This paper considers the problem of pricing American options when the dynamics of the underlying are driven by both stochastic volatility following a square-root process as used by Heston [Rev. Financial Stud., 1993, 6, 327–343], and by a Poisson jump process as introduced by Merton [J. Financial Econ., 1976, 3, 125–144]. Probability arguments are invoked to find a representation of the solution in terms of expectations over the joint distribution of the underlying process. A combination of Fourier transform in the log stock price and Laplace transform in the volatility is then applied to find the transition probability density function of the underlying process. It turns out that the price is given by an integral dependent upon the early exercise surface, for which a corresponding integral equation is obtained. The solution generalizes in an intuitive way the structure of the solution to the corresponding European option pricing problem obtained by Scott [Math. Finance, 1997, 7(4), 413–426], but here in the case of a call option and constant interest rates.     

An empirical test of the Brennan-Schwartz bond pricing model in the Australian context

This paper presents an empirical test of some aspects of the Brennan and Schwartz arbitrage bond pricing model. Specifically it evaluates the assumed discrete version of the joint interest process for the short and long rates by estimating it for a series of sample periods under varying market conditions. The implications of the specified form of these two interest rates within the context of hypotheses of interest rate behaviour are also examined. The bond valuation model is tested for bond price index data. The model is found to have a consistent estimation error of 10% and predominantly overestimated the actual price index. The performance of the model is not found to be sensitive to the value of the utility dependent parameter.We thank seminar participants at the University of New South Wales, the Australian National University, and participants at the Inaugural International Conference on Asian-Pacific Financial Markets, November 16–18, 1989, the National University of Singapore for many helpful comments and suggestions. We are responsible for any remaining errors.     

An evolutionary CAPM under heterogeneous beliefs

Heterogeneity and evolutionary behaviour of investors are two of the most important characteristics of financial markets. This paper incorporates the adaptive behaviour of agents with heterogeneous beliefs and establishes an evolutionary capital asset pricing model (ECAPM) within the mean-variance framework. We show that the rational behaviour of agents switching to better-performing trading strategies can cause large deviations of the market price from the fundamental value of one asset to spill over to other assets. Also, this spill-over effect is associated with high trading volumes and persistent volatility characterized by significantly decaying autocorrelations of, and positive correlation between, price volatility and trading volume.     

Modelling the Currency Forward Risk Premium: A New Perspective

In this paper we seek to develop a new approach to the time series analysis of foreign exchange risk premia. We do so by assuming a geometric Brownian process for the spot exchange rate and expressing the no-arbitrage spot-forward price relationship under the historical probability measure. We are thereby able to obtain a stochastic differential equation system linking the spot exchange rate, the forward exchange rate and the risk premium (modelled directly as a mean-reverting diffusion process) which we estimate using Kalman filtering techniques. We are able to use observations at a range of frequencies since the framework we set up does not involve overlapping observations. The model is then applied to the French Franc/USD, DEM/USD, GBP/USD, and Japanese Yen/USD exchange rates from 1 January 1990 to 31 December 1998. For all currencies we find evidence that the forward risk premium is stationary and exhibits substantial positive time variation.     

The dynamic operation of the market for partnership deeds in a duopolistic industry of a profit-maximizing firm and workers' enterprise

This paper analyses a model of the dynamic interaction of a profit-maximizing firm and a workers' enterprise (in the sense of Sertel, 1982) in an industry in which each acts as a duopolist. The framework is similar to that of Chiarella (1992). In that study labour was the only factor of production and workers were allowed to trade-off work and leisure. Here we wish to analyse the effect of the capital accumulation decision on the outcome of the duopolistic competition. In order to obtain a tractable model we drop the work-leisure trade-off. We assume dynamic adjustment in the market for partnership deeds along the lines suggested by Okuguchi (1992a, b) and analyse the equilibrium of the duopoly, its comparative statics and stability with respect to key variables.