Does product complexity matter for competition in experimental retail markets?

We describe a first experiment on whether product complexity affects competition and consumers in retail markets. We are unable to detect a significant effect of product complexity on prices, except insofar as the demand elasticity for complex products is higher. However, there is qualified evidence that complex products have the potential to induce consumers to buy more than they would otherwise. In this sense, consumer exploitability in quantities cannot be ruled out. We also find evidence for shaping effects: consumers’ preferences are shaped by past experience with prices, and firms may in principle exploit this to sell more.     

Data skeletons: simultaneous estimation of multiple quantiles for massive streaming datasets with applications to density estimation

We consider the problem of density estimation when the data is in the form of a continuous stream with no fixed length. In this setting, implementations of the usual methods of density estimation such as kernel density estimation are problematic. We propose a method of density estimation for massive datasets that is based upon taking the derivative of a smooth curve that has been fit through a set of quantile estimates. To achieve this, a low-storage, single-pass, sequential method is proposed for simultaneous estimation of multiple quantiles for massive datasets that form the basis of this method of density estimation. For comparison, we also consider a sequential kernel density estimator. The proposed methods are shown through simulation study to perform well and to have several distinct advantages over existing methods.     

On the Breslow–Holubkov estimator

Breslow and Holubkov (J Roy Stat Soc B 59:447–461 1997a) developed semiparametric maximum likelihood estimation for two-phase studies with a case–control first phase under a logistic regression model and noted that, apart for the overall intercept term, it was the same as the semiparametric estimator for two-phase studies with a prospective first phase developed in Scott and Wild (Biometrica 84:57–71 1997). In this paper we extend the Breslow–Holubkov result to general binary regression models and show that it has a very simple relationship with its prospective first-phase counterpart. We also explore why the design of the first phase only affects the intercept of a logistic model, simplify the calculation of standard errors, establish the semiparametric efficiency of the Breslow–Holubkov estimator and derive its asymptotic distribution in the general case.     

The birthday problem

Happy Birthday! If it is not your birthday today, it may well be the birthday of someone in your office, or in your class at school. Possibly, it is the birthday of two people in your office or your class. Just how big does a group have to be before its members are likely to share a birthday? Mario Cortina Borja and John Haigh explain the birthday problem.     

H-likelihood: problems and solutions

In recent issues of this journal it has been asserted in two papers that the use of h-likelihood is wrong, in the sense of giving unsatisfactory estimates of some parameters for binary data (Kuk and Cheng, 1999; Waddington and Thompson, 2004) or theoretically unsound (Kuk and Cheng, 1999). We wish to refute both these assertions.     

Naturing the Nation: Aliens,Apocalypse, and the Postcolonial State

The purpose of this study is to understand how the British Canadian Frank Schofield transformed himself into an established missionary scholar and nobleman in Korea. The study employs its framework from the structure of cultural exchange itself in its survey of Schofield's career. It examines the relevant aspects of Korean and Western cultures, and the characteristics of Schofield who linked them. The case, including themes significant both to Korean and Western cultures, such as the importance of spirituality, an emphasis on education, and the ideals of justice and love, explains reasons for his success as a cultural mediator between Korea and the West. It reveals that the flow of information and ideas between Koreans and Schofield illustrates the ability of intercultural contact to influence the initiating as well as receiving culture. It suggests that such a distinction between sender and receiver may carry little ultimate significance. Finally, it argues that individuals of different cultures can convey information and ideas effectively only if the conveyer learns about the target individuals for the information and ideas, and communicates on the basis of that knowledge, as intercultural communications occur between the individuals of different cultures.     

Reflections on liberalism,policulturalism, and ID-ology: citizenship and difference in South Africa

How do nation-states in the twenty-first century, nation-states increasingly forced to come to terms with the ethnic heterogeneity of their citizens, deal with the problem of cultural difference? How, in particular, does the Constitution of post-apartheid South Africa — widely believed to be the most enlightened in the contemporary world, the most tolerant of diversity — strike a balance between the ‘One Law’ of ‘The Nation’ and the plurality of customary beliefs sustained, as a matter of right, by the various peoples who make up this postcolony? What happens, in the course of everyday existence, when Constitution and Custom appear to contradict one another — and to do so in such a manner as to raise questions of basic human rights, of freedom of belief, even of life-and-death? These questions are addressed in the paper through a critical, broadly situated analysis of the confrontation between the Constitution of South Africa and the Kingdom of Custom that continues to prevail in one of its provinces, the North West. By exploring a complicated case that drew the State, via its Human Rights Commission, into open conflict with a Tswana chiefdom — a case about death rituals argued, before a high court judge, in the lexicon of modern jurisprudence — it shows how a ‘living constitution’, tolerant of everyday ambiguity, is being forged in the space of strategic engagement opened up by the alternative languages and cultures of legality that exist in this ‘policultural’ postcolony. And in others like it.     

A political profile of Protestant minorities in Europe

This article uses a large volume of data – in particular, surveys – to explore the character of Protestant identity in contemporary European states. It distinguishes three contexts. First, in the Nordic and certain adjacent states, the dominance of Protestantism was complete, but more recent secularisation has provoked a reaction from Christian parties, which enjoy strong support from active Protestants. Second, in certain states that in the past were predominantly Protestant, and where the ethos of the state was aggressively so, a significant Catholic minority was counter-mobilised politically, but as the dominant state-building parties became increasingly secular, committed Protestants reacted in different ways, including the formation of splinter parties (as in the Netherlands and Switzerland) or working within the traditional parties (as in Great Britain and Germany). Third, in a few states there has traditionally been a small Protestant minority, which has played a significant role in national development, but in these cases (mainly successor states to the Habsburg monarchy) decades of communist rule have largely obliterated what might have been distinctive patterns of political behaviour. The article explores variation in group identity patterns and in attitudes towards the state in those cases for which appropriate survey data are available, and devotes particular attention to the position within the United Kingdom, where religion has played a prominent role in the state- and nation-building process.     

Topics in Microbial Risk Assessment: Dynamic Flow Tree Process

Microbial risk assessment is emerging as a new discipline in risk assessment. A systematic approach to microbial risk assessment is presented that employs data analysis for developing parsimonious models and accounts formally for the variability and uncertainty of model inputs using analysis of variance and Monte Carlo simulation. The purpose of the paper is to raise and examine issues in conducting microbial risk assessments. The enteric pathogen Escherichia coli O157:H7 was selected as an example for this study due to its significance to public health. The framework for our work is consistent with the risk assessment components described by the National Research Council in 1983 (hazard identification; exposure assessment; dose-response assessment; and risk characterization). Exposure assessment focuses on hamburgers, cooked a range of temperatures from rare to well done, the latter typical for fast food restaurants. Features of the model include predictive microbiology components that account for random stochastic growth and death of organisms in hamburger. For dose-response modeling, Shigella data from human feeding studies were used as a surrogate for E. coli O157:H7. Risks were calculated using a threshold model and an alternative nonthreshold model. The 95% probability intervals for risk of illness for product cooked to a given internal temperature spanned five orders of magnitude for these models. The existence of even a small threshold has a dramatic impact on the estimated risk.     

How planning and capital budgeting improve SME performance

This paper focuses on the use of strategic planning among small and medium sized enterprises (SMEs) in the UK manufacturing sector. It analyses the relationship between the intensity of strategic planning, business objectives, perceived performance, changes in the business environment and the use of capital budgeting techniques. Capital budgeting is of particular interest as an area of investigation, and is one which has seldom featured in previous studies of strategic planning behaviour. These issues were investigated via a survey of UK manufacturing SMEs carried out in the winter of 1996/97.

The key results suggest that SMEs incorporate a range of objectives into their strategic planning process, with profit improvement perceived to be the most important objective, followed by sales growth. SMEs engaged in detailed strategic planning are more likely to use formal capital budgeting techniques, including the net present value method, which is consistent with maximising the companys' value. Perceived profitability and success in achieving organisational objectives were positively associated with planning detail, suggesting that strategic planning is a key component improving performance. Planning detail was also associated with a significantly higher level of perceived change in the business environment.