Hierarchical priors for Bayesian CART shrinkage

The Bayesian CART (classification and regression tree) approach proposed by Chipman, George and McCulloch (1998) entails putting a prior distribution on the set of all CART models and then using stochastic search to select a model. The main thrust of this paper is to propose a new class of hierarchical priors which enhance the potential of this Bayesian approach. These priors indicate a preference for smooth local mean structure, resulting in tree models which shrink predictions from adjacent terminal node towards each other. Past methods for tree shrinkage have searched for trees without shrinking, and applied shrinkage to the identified tree only after the search. By using hierarchical priors in the stochastic search, the proposed method searches for shrunk trees that fit well and improves the tree through shrinkage of predictions.     

A small sample confidence interval for autoregressive parameters

This paper is concerned with interval estimation of an autoregressive parameter when the parameter space allows for magnitudes outside the unit interval. In this case, intervals based on the least-squares estimator tend to require a high level of numerical computation and can be unreliable for small sample sizes. Intervals based on the asymptotic distribution of instrumental variable estimators provide an alternative. If the instrument is taken to be the sign function, the interval is centered at the Cauchy estimator and a large sample interval can be created by estimating the standard error of this estimator. The interval proposed in this paper avoids estimating this standard error and results in a small sample improvement in coverage probability. In fact, small sample coverage is exact when the innovations come from a normal distribution.     

From Strength to Strength: An Interview with Russell Deal

Russell Deal is the founder and managing director of Innovative Resources, the publishing arm of St. Luke's Anglicare, Bendigo. Russell is a social worker, who for the past 13 years has been a publisher. Strength Cards, now a widely used resource all over the world, were followed by The Bears, and more recently by Koala Company, Name the Frame, Mates Traits and many other resources designed to address a range of situations with individuals, families, teams and communities. Details available at www.innovativeresources.org     

The View from the Top: Senior Executives' Perceptions of Changing Management Practices in UK Companies1

There is a growing literature which suggests that the 1980s witnessed significant, even unprecedented changes in the management of organizations. This paper contributes to that literature by providing questionnaire and interview-based evidence of senior managers' perceptions of recent changes in management practice in large and medium-sized firms in the UK. The findings cover three main areas: the changing context of management practice; change initiatives in the areas of human resource management (HRM) and management levels; and the degree of success in managing change. Our findings suggest that senior managers perceive rapid and continuous change within the UK corporate sector. We conclude by suggesting that the changes reported appear to be of degree rather than a radical break with past management practices and that inconsistent means of facilitating change are seemingly being deployed.     

Production technology and management in planned and market economies

This paper discusses how technological innovation takes place in manufacturing industry, and especially in the engineering sector, contrasting in particular the effects of the Western market economy, and the East European planned economy. The relative lack of cross-influence between formal scientific research and actual industrial innovation practice in this area is first discussed. Comparative studies of engineering practice in planned and market economies are described which point to the important influence of the economic environment on innovation practice in the factory's design office, and on the shop-floor. The East European Soviet Type Economy is seen to have features which in the light of recent Western empirical studies into industrial innovation, must hamper this process. In particular it is proposed that its relative economic and social rigidity has an important restricting influence on the actual process of innovation in the factory.