Calibration Weighting Methods for Complex Surveys

This paper presents a careful investigation of the three popular calibration weighting methods: (i) generalised regression; (ii) generalised exponential tilting and (iii) generalised pseudo empirical likelihood, with a major focus on computational aspects of the methods and some empirical evidences on calibrated weights. We also propose a simple weight trimming method for range‐restricted calibration. The finite sample behaviour of the weights obtained by the three calibration weighting methods and the effectiveness of the proposed weight trimming method are examined through limited simulation studies.     

Preventing drowning through design – the contribution of human factors

A number of routes can be followed towards the prevention of drowning, such as educating on water safety, installing barriers between non-intended users and water, mitigating the consequences of submersion incidents, and design. The human factor approach to safety is that design should always be the primary route. Human factors can be applied to the design of personal protective equipment such as buoyancy aids, barriers such as pool fencing, ancillary equipment such as swimming pool covers through to information and organisational factors such as safety signs and swimming campaigns. Design should consider all potential drowning scenarios and accommodate the characteristics of those at risk. A framework is presented with examples on how human factor principles can be applied to the design of potential drowning sites and products, with suggestions for methods and techniques that can be used in the key stages of predicting potential hazards and assessing risk.     

Multiperiod hedging in the presence of stochastic volatility

In this paper, we characterize the multiperiod minimum-risk hedge strategy within the stochastic volatility (SV) framework and compare it to other hedge strategies on the basis of hedging performance. Using crude oil markets as an example, we demonstrate that the SV model is appropriate in depicting price behaviour. However, ex ante and ex post comparisons indicate that the SV strategy is inferior to conventional hedging strategies. There is also evidence that the Generalized Autoregressive Conditional Heteroskedasticity (GARCH) strategy may be better than the SV strategy, at least in terms of variance reduction.     

An analysis of the profitability of businesses of diversified companies

This paper presents empirical evidence on the relationship between diversification and profitability. The data set used in the analysis includes data on 55 U.S. corporations who participated in phase II of the project on Profit Impact of Market Strategy (PIMS).Following upon the pioneering work of Carl Kaysen, complex indices of diversification are developed. Cross sectional regression analyses indicate a statistically significant positive association between measures of corporate diversification and measures of business profitability (return on investment or profit margin on sales). These relationships are insensitive to variations in the treatment of outliers, and do not appear to be accounting artifacts.     

Ex Ante Stock Market Return Volatility Implied by the OEX Option Premium

Previous empirical evidence suggests that stock return volatility expectations change over time, but the existing models of time-varying variance lack a theoretical structure that is rigorously linked to the efficient markets dividend discount model. This paper develops and tests such a model. The conditional forecast variance of the return on the stock market portfolio is expressed as a linear combination of the adjusted conditional forecast variance of the interest rate and the dividend growth rate. An empirical test using the implied variance of the S&P 100 index option provides evidence that supports the model's predictions.     

Decomposing hospital productivity changes, 1985–1988: A nonparametric Malmquist approach

Annual data on U.S. hospitals from 1985–1988 are evaluated by ownership type—profit, nonprofit, state and local government, and U.S. Department of Veterans Affairs (VA)—for changes in hospital productivity over time. Distance functions are used to measure Malmquist indices of productivity change, which are then decomposed into indices of efficiency change and technology change. In contrast to previous studies using this approach, we allow for variable returns to scale and use both input and output orientations. We find that changes in technology dominate changes in inefficiency in determining changes in productivity.     

Success factors for collaborative product development: a study of suppliers of information and communication technology

It is apparent that more and more organizations are embarking on collaborative ventures to develop products. This is particularly evident in Information and Communication Technology (ICT) sectors, so much so that part of the 'received wisdom' of ICT companies is that collaboration is the preferred route for product development. The benefits of collaboration have been well documented and are linked to the complexity and costliness of product development and the need for inputs from wide and varied areas of expertise as well as shorter lead times for product development. But the risks and costs of collsborative product development have been less well defined. In this paper, it is argued that the alleged rewards of collaboration may not be experienced in practice and that collaboration can lengthen the product development process, add to the cost of product development and prove difficult to control. However, management practice can facilitate the effective outcome of collaborative product development and the critical factors affecting the likelihood of successful management practice are presented here.