Simulating the Evolution of the Implied Distribution

Motivated by the implied stochastic volatility literature (Britten–Jones and Neuberger, forthcoming; Derman and Kani, 1997; Ledoit and Santa–Clara, 1998) this paper proposes a new and general method for constructing smile–consistent stochastic volatility models. The method is developed by recognising that option pricing and hedging can be accomplished via the simulation of the implied risk neutral distribution. We devise an algorithm for the simulation of the implied distribution, when the first two moments change over time. The algorithm can be implemented easily, and it is based on an economic interpretation of the concept of mixture of distributions. It can also be generalised to cases where more complicated forms for the mixture are assumed.     

A maximum likelihood approach to estimating dynamic models with unobserved independent variables

A maximum likelihood method to estimate the parameters of dynamic models containing unobserved independent variables is proposed. The approach is to maximize the likelihood of the residuals produced by the recursive Kalman filter equations applied to the model in state-space form. A simulation study is presented comparing the proposed method to the instrumental variable approach. An example using real data is given which estimates models of the Permanent-Income Hypothesis.     

Annual Reporting Mechanisms of National Health Service Trusts

This article investigates the role of the annual report and the annual general meeting (AGM) in the context of NHS trusts. The authors report the results of a questionnaire survey of every NHS trust in the UK. Significant variation in the approach taken within a common framework of accountability was found. In general, there seems to be little public demand for trusts' annual reports and attendance at their AGMs was low. The research indicates possibilities of extending annual reporting in the public sector beyond the annual report and AGM and discloses innovative ways that trusts have attempted to overcome the limited interest of stakeholders produced by the traditional reporting mechanisms.     

Time diversification and security preferences: A stochastic dominance analysis

We use stochastic dominance to test whether investor should prefer riskier securities as the investment horizon lengthens. Return distributions for stocks, bonds, and U.S. Treasury bills are generated for holding periods of one to 25 years by simulation. For each holding period, stochastic dominance tests are run to establish preferences between the alternative security classes. Contrary to previous mean-variance based studies, we find no evidence that high-risk securities (stocks) dominate low-risk securities (bonds, Treasury bills) as the investment horizon lengthens. However, we do find that corporate bonds systematically dominate government bonds.     

Daily mutual fund flows and redemption policies

We examine how redemption policies affect daily fund flows in open-end mutual funds. Since short-term trading of fund shares, as manifested in daily fund flows, can have an adverse impact on returns to the fund’s shareholders, mutual funds might find it desirable to discourage short-term trading through the use of redemption fees. However, if daily fund flows are due to fund shareholders’ legitimate liquidity demands, the redemption fee would have little effect on daily fund flows and possibly adversely affect fund shareholders by imposing a liquidity cost on them. We find that the likelihood of a fund charging a redemption fee is largely a function of its overall fee structure. We also use a sample of funds that imposed redemption fees to examine whether the distribution of daily fund flows changes after the initiation of the redemption fee. We find that the redemption fee is an effective tool in controlling the volatility of fund flows.     

Asset Revaluations in the Accounts of UK National Health Service Trusts

This paper reports the results of an investigation into the impact of the revaluation of fixed assets on the reported results of NHS ambulance services. It recalculates the accounting rate of return of individual trusts after removing revaluation adjustments and examines the published responses of trusts. The numerical analysis demonstrates that, in general, revaluation has depressed the stated rate of return in an inconsistent manner. Failure to meet the required rate of return may cause a trust to be subjected to additional monitoring and management reorganisation while the trusts respond by explaining deviations in the accounting return measure by referring to revaluations and other technical adjustments. Management decisions made in response to these accounting measures may be sub-optimal in delivering health care but appropriate in achieving the desired accounting outcome.     

Competition and Efficiency after Privatization: The Role of the NAO

One of the arguments for privatization is to promote market competition in order to facilitate efficiency gains. This review of NAO privatization reports shows that the promotion of competition is rarely stated as an objective of a privatization and, where it is, it can lead to difficulties in drawing objective audit conclusions. The work of the regulators is of considerable importance after privatization; and a more recent role for the NAO is that of responsibility for the financial audit and value-for-money studies of these regulators. These NAO studies provide new opportunities to review the effectiveness of the regulators and to promote accountability in competition policy after privatization.