Stochastic volatility with leverage: Fast and efficient likelihood inference

This paper is concerned with the Bayesian analysis of stochastic volatility (SV) models with leverage. Specifically, the paper shows how the often used Kim et al. [1998. Stochastic volatility: likelihood inference and comparison with ARCH models. Review of Economic Studies 65, 361–393] method that was developed for SV models without leverage can be extended to models with leverage. The approach relies on the novel idea of approximating the joint distribution of the outcome and volatility innovations by a suitably constructed ten-component mixture of bivariate normal distributions. The resulting posterior distribution is summarized by MCMC methods and the small approximation error in working with the mixture approximation is corrected by a reweighting procedure. The overall procedure is fast and highly efficient. We illustrate the ideas on daily returns of the Tokyo Stock Price Index. Finally, extensions of the method are described for superposition models (where the log-volatility is made up of a linear combination of heterogenous and independent autoregressions) and heavy-tailed error distributions (student and log-normal).     

Output sharing in partnerships as a common pool resource management instrument

Many economic environments are susceptible to either free-riding or overuse. Common pool resources (CPRs) fall in the latter category. Equally sharing the output of a CPR in partnerships introduces a free-riding incentive that may offset overuse. Socially optimal harvesting can be induced by dividing the set of resource users into a number of partnerships in such a way that each resource users’ tendency to over-harvest from the resource is exactly offset by his or her tendency to free-ride on the contributions of others. We conduct a laboratory experiment to assess the performance of this partnership solution by introducing equal-sharing subgroups of size one, four and six into a twelve-person CPR environment. Group assignment is either unchanging throughout a 15 period session or randomly mixed each decision round. Group size significantly affects aggregate effort, while group assignment makes no significant difference. The distribution of total payoffs is more equitable for randomly mixed groups. Implications of our results for voluntary and centralized implementations of the partnership solution are discussed.

创新商品化与六西格玛

有时创新的最难之处就在于突破想象。你的创新活动是否总是停滞于此呢?是否觉得想出好创意后却很难将其付诸实施呢?实际上,所有创新都是一套全方位的解决方案,它们集出色的创意、实施创意的全面计划以及根据计     

Professional accountants and the development of a management accounting service for the small firm: barriers and possibilities

This paper reports the results of a qualitative study examining the potential for the provision of a management accounting service for smaller companies by accountants in professional practice. The study aimed to determine the management information needs of owner-managers, the type and frequency of information preferred and the capacity of professional accountants to contribute to these needs. The owner-managers of 15 smaller companies were asked to participate in semi-strucutured interviews during which their use of computers to provide management accounts, their relationship with their accountant and their financial skills were discussed. The respondents were presented with a range of management information including statutory final accounts, interim accounts, cash statements, ratios and graphical comparisons of monthly turnover figures in order to assess their financial information skills and needs. The study found that companies used computers for the preparation of management accounting information, but usually not to their full potential. The financial awareness of owner-managers varied considerably. There was a favourable response to the presentation of ratios and graphs, however, it was felt that an explanation or interpretation of financial information by their accountant would be a useful addition to improve their understanding and therefore aid their business. The study concludes that there appears to be significant potential for accountants to expand the management accounting services they provide to smaller companies, especially where information is presented as ratios or graphs and accompanied with an appropriate narrative interpretation. This would also increase the financial skills of their clients and result in an increased demand for management accounting services.     

Sliding Scales and Wage Flexibility in 1920s Britain

This note uses a cross-section of industry-level wage and unemployment rate information for early 1920s Britain to demonstrate that, in general, sliding scales had little impact on wage settlements. The evidence overwhelmingly suggests that industries which had an above-average unemployment rate in the early 1920s experienced a disproportionate fall in nominal wages. There are also compositional effects in the sample which suggest that industries which had a predominantly male workforce, or were highly exposed to international competition in product markets, saw above-average rates of wage deflation.     

Stochastic Volatility: Likelihood Inference and Comparison with ARCH Models

In this paper, Markov chain Monte Carlo sampling methods are exploited to provide a unified, practical likelihood-based framework for the analysis of stochastic volatility models. A highly effective method is developed that samples all the unobserved volatilities at once using an approximating offset mixture model, followed by an importance reweighting procedure. This approach is compared with several alternative methods using real data. The paper also develops simulation-based methods for filtering, likelihood evaluation and model failure diagnostics. The issue of model choice using non-nested likelihood ratios and Bayes factors is also investigated. These methods are used to compare the fit of stochastic volatility and GARCH models. All the procedures are illustrated in detail.