A Simple Estimator of Two-Dimensional Copulas,with Applications1

Copulas are distributions with uniform marginals. Non-parametric copula estimates may violate the uniformity condition in finite samples. We look at whether it is possible to obtain valid piecewise linear copula densities by triangulation. The copula property imposes strict constraints on design points, making an equi-spaced grid a natural starting point. However, the mixed-integer nature of the problem makes a pure triangulation approach impractical on fine grids. As an alternative, we study the ways of approximating copula densities with triangular functions which guarantees that the estimator is a valid copula density. The family of resulting estimators can be viewed as a non-parametric MLE of B-spline coefficients on possibly non-equally spaced grids under simple linear constraints. As such, it can be easily solved using standard convex optimization tools and allows for a degree of localization. A simulation study shows an attractive performance of the estimator in small samples and compares it with some of the leading alternatives. We demonstrate empirical relevance of our approach using three applications. In the first application, we investigate how the body mass index of children depends on that of parents. In the second application, we construct a bivariate copula underlying the Gibson paradox from macroeconomics. In the third application, we show the benefit of using our approach in testing the null of independence against the alternative of an arbitrary dependence pattern.     

Virtual Experiments and Their Use in Teaching Experimental Design

The ability to design experiments in an appropriate and efficient way is an important skill, but students typically have little opportunity to get that experience. Most textbooks introduce standard general‐purpose designs, and then proceed with the analysis of data already collected. In this paper we explore a tool for gaining design experience: computer‐based virtual experiments. These are software environments which mimic a real situation of interest and invite the user to collect data to answer a research question. Two prototype environments are described. The first one is suitable for a course that deals with screening or response surface designs, the second one allows experimenting with block and row‐column designs. They are parts of a collection we developed called ENV2EXP, and can be freely used over the web. We also describe our experience in using them in several courses over the last few years.     

The political economy of housing prices: Hedonic pricing with regression discontinuity

This paper uses hedonic pricing to empirically estimate the value of publicly provided local goods and services in the constituencies of the ruling party relative to those of the opposition parties. To improve control for omitted variables that change smoothly over space, we use a regression discontinuity design to restrict the sample to houses that are near the electoral boundaries. Using resale market prices of public flats in Singapore, in some cases we find a moderate but highly statistically significant difference in housing prices across the electoral boundaries that separate the constituencies of the ruling party and the opposition parties.     

International perspectives on tourism‐led development: some lessons for the SDIs

The concept of tourism‐led socio‐economic development is neither new nor peculiar to South Africa. This study draws on the international experience of the Malindi‐Mombasa coastal development corridor in Kenya, the Goa Coast of India, the Kulu Valley and Bhutan in the Himalayas, the Gambia, Dominica, Belize and the Maldives. It assesses the results achieved in these tourism programmes against the strategic objectives of those South African SDIs that place a heavy emphasis on the country's tourism potential. The SDIs, as described elsewhere in this collection, represent a new paradigm adopted by the South African government, aimed at moving away from a protected and isolated approach to economic development, towards one in which international competitiveness, regional cooperation and a more diversified ownership base are paramount. The key objectives of the tourism‐led development corridors, including the Wild Coast and Lubombo SDIs, are to generate sustainable economic growth and development; generate sustainable long‐term employment creation; maximise the extent to which private sector investment and lending can be mobilised into the process; change the ownership base of the industry so that people previously excluded from the mainstream of the economy by discriminatory practices can play a meaningful role as workers, managers and owners of new tourism enterprises; and to exploit the opportunities that arise from new tourism and ecotourism developments for the creation of upstream and downstream business opportunities, especially small businesses owned by previously marginalised groups.     

An axiomatic characterization of preferences under uncertainty: Weakening the independence axiom

The independence axiom used to derive the expected utility representation of preferences over lotteries is replaced by requiring only convexity, in terms of probability mixtures, of indifference sets. Two axiomatic characterizations are proven, one for simple measures and the other continuous and for all probability measures. The representations are structurally similar to expected utility, and are unique up to a generalization of affine transformations. First-order stochastic dominance and risk aversion are discussed using a method which finds an expected utility approximation to these preferences without requiring differentiability of the preference functional.     

The influence of the introduction of accounting disclosure regulation on mandatory disclosure compliance: Evidence from Jordan

This paper examines the influence of accounting disclosure regulation, governance reforms and ownership changes, resulting from privatisation, on mandatory disclosure compliance of a sample of 80 non-financial, listed Jordanian companies for the years 1996 and 2004. Employing two checklists based on the International Financial Reporting Standards (IFRS) extant in the years 1996 and 2004, we find that disclosure compliance with the IFRS is significantly higher in 2004 than that in 1996. Our multiple regression results indicate that disclosure regulation reforms produced the most significant influence on mandatory disclosure compliance. Further, governance reforms through the mandate of audit committees emerged as a significant determinant of compliance with mandatory disclosure requirements.     

Researching the future: method or madness?

This paper examines the methodological issues behind futures studies, questioning whether it is possible to claim a futures study as methodologically ‘sound’, and critiquing how futures methodology fits within the methodological paradigms currently recognised in the research field. The extent to which futures methodology can be considered a paradigm in its own right is also examined as are the assumptive foundations of futures studies. While all the evidence raises many questions as to the form of futures methodology, the lack of clarity does not make a futures study invalid or unreliable, and hence sensemaking from the chaos of futures ‘data’ does ensure that futures studies can be based on method rather than madness.

How does one research the future? The very notion of researching the future is a paradox. The word research lies within the time boundaries of the past and the present so to research the future appears a logical impossibility. Attempts to ground the methodology in any single paradigm or set of constructs proves a fruitless task. Indeed, it becomes apparent that when undertaking research into an area that is something new, in the future, which could constitute a new field of research, fundamentally a new methodology needs to be created. This paper discusses how the development of a futures methodology is an on-going process which cannot be bounded by the limitations of strict rigour, but is nevertheless a rigorously sound approach to carrying out research.

When researching the future, no one method is appropriate in isolation. While quantitative methods such as forecasting, extrapolation and time series may prove useful if there is raw numerical data to work with, a hypothesis cannot be tested and proven as is the case in many quantitative studies. Given the nature of ‘the future’ itself, raw quantitative analysis needs contextualising and interpreting in light of the assumptive future constructs, and the assumptions themselves need examining for ‘assumption drag’ so that underlying trends and wave patterns are accounted for [1].     

A review of current A/AS syllabuses in Design and Technology

Concluding remarks It can be seen that the common core has brought a great deal of consistency between the syllabuses. There was a belief that A-levels would be restructured as a result of the National debate about core skills for A-levels, but this now seems to have been shelved. The pressure now is from the evolving form of National Curriculum Technology and the search for continuity and progression and from the developing relationship with other 16–19 courses, e.g. BTEC (Business and Technician education Council). The recent paper by Smithers and Robinson (1992) failed to add very much to the debate as a result of the rather simplistic and divisive view it presented.The review of A and AS-levels in Design and Technology is due to begin in the near future. It is essential that a full representation of the issues and complexities of this field is made so that developments can be soundly based. Design and Technology has made great strides at A and AS-level and it is vital to ensure that this progress is both recognised and sustained through the review process.     

Integrated Bayesian decision: A case

The process described in this article provides a framework for combining the judgments and experiences of each member of a decision-making unit. Utilizing the Bayesian approach to decision-making and the Jury of Executive Opinion the model may be of assistance to management teams, Boards of Directors and committees in reaching a consensus on critical decisions. The data are based on an actual case experience familiar to the authors.