USE OF A LOG-LINEAR MODEL TO COMPUTE THE EMPIRICAL SURVIVAL CURVE FROM INTERVAL-CENSORED DATA, WITH APPLICATION TO DATA ON TESTS FOR HIV POSITIVITY

We describe how a log-linear model can be used to compute the nonparametric maximum likelihood estimate of the survival curve from interval-censored data. This permits such computation to be performed with the aid of readily available statistical software such as GLIM or SAS. The method is illustrated with reference to data from a cohort of Danish homosexual men, each of whom was tested for HIV positivity on one or more of six possible follow-up times.     

Homosexuality in Dakar: Is the Bed the Heart of a Sexual Subculture?

In Dakar, Senegal, a bar forms a meeting place for a group of men who have sex with other men. In an original study, the author profiles this group and explains how cultural as well as economic forces shape meaning in these men’s lives. To place this study in context, the author provides a review of the anthropological literature concerning same-sex behavior in Africa. The author argues that the social formations in which men who have sex with men operate cannot explain their sexual personae, nor can sexual practices be explained by the cultural models that describe them.     

STATISTICAL CHALLENGES OF AIDS: (The 1990 Knibbs Lecture, Canberra, 27 November 1990)

Issues that are central to the understanding and management of the HIV epidemic have generated numerous statistical challenges. This paper considers questions concerning the incubation period, the effects of treatments, pre diction of AIDS cases, the choice of surrogate end points for the assessment of treatments and design of strategies for screening blood samples. These issues give rise to a broad range of intriguing problems for statisticians. We describe some of these problems, how they have been tackled so far and what remains to be done. The discussion touches on topical statistical methods such as smoothing, bootstrapping, interval censoring and the ill-posed inverse problem, as well as asking fundamental questions for frequentist statistics.     

Playful organisations: Undecidability as a scarce resource

This article explores how organisational play becomes a managerial tool to increase and benefit from undecidability. The article draws on Niklas Luhmann's concept of decision and on Gregory Bateson's theory of play to create a conceptual framework for analysing the relation between decision and undecidability. With an empirical point of departure in Danish public school policy and two concrete examples of games utilised in school development, the article analyses how play is a way for organisations to simultaneously decide and also avoid making a decision, thus keeping flexibility and possibilities intact. In its final sections, the article discusses what happens to conditions of decision-making when organisations do not just see undecidability as a given condition, but as a limited resource indispensable for change and renewal. The article advances discussions of organisational play by exploring the consequences play has for the very conditions of organising and for key concepts in organisation theory.     

Integrating Poverty and Environmental Concerns into Value‐Chain Analysis: A Strategic Framework and Practical Guide

This article aims to guide the design and implementation of action‐research projects in value‐chain analysis by presenting a strategic framework focused on small producers and trading and processing firms in developing countries. Its stepwise approach – building on the conceptual framework set out in a companion article – covers in detail what to do, questions to be asked and issues to be considered, and integrates poverty, gender, labour and environmental concerns.‘Upgrading’ strategies potentially available for improving value‐chain participation for small producers are identified, with the ultimate purpose of increasing the rewards and/or reducing the risks.     

Three Routes to Pension Reform: Politics and Institutions in Reforming Pensions in Denmark,Finland and Sweden

By analysing pension reforms in three Nordic countries – Denmark, Finland and Sweden – that apply different institutional solutions in their old‐age security programmes, this article argues that the political processes that shaped the country‐specific pension set‐ups in the 1950s and 1960s had important ramifications for subsequent reform possibilities. A high degree of inertia exists not only in the institutions themselves but also in the political reform options and the ways in which pensions were reformed. The analysis shows that the ‘new politics’ was not new in any of the three countries. Furthermore, given the differences in the three cases, the analysis questions the nature of pension reform. The Swedish reform in the late 1990s was a ‘big bang’ that eliminated the old and changed everything; the Finns built on piecemeal reforms of conversion that gradually changed the whole system; and, while the Danish story appears to be one of stability and status quo, the drift of Danish policy ultimately changed the basic characteristics of the system. Although all three countries have more or less thoroughly reformed their pensions, the reform processes have differed according to both historical legacies and institutional frameworks.