A graphical analysis of some basic results in social choice

We use a simple graphical approach to represent Social Welfare Functions that satisfy Independence of Irrelevant Alternatives and Anonymity. This approach allows us to provide simple and illustrative proofs of May's Theorem, of variants of classic impossibility results, and of a recent result on the robustness of Majority Rule due to Maskin (1995). In each case, geometry provides new insights on the working and interplay of the axioms, and suggests new results including a new characterization of the entire class of Majority Rule SWFs, a strengthening of May's Theorem, and a new version of Maskin's Theorem. Received: 31 July 1999/Accepted: 27 March 2001     

Copula structure analysis

Summary.  We extend the standard approach of correlation structure analysis for dimension reduction of high dimensional statistical data. The classical assumption of a linear model for the distribution of a random vector is replaced by the weaker assumption of a model for the copula. For elliptical copulas a correlation-like structure remains, but different margins and non-existence of moments are possible. After introducing the new concept and deriving some theoretical results we observe in a simulation study the performance of the estimators: the theoretical asymptotic behaviour of the statistics can be observed even for small sample sizes. Finally, we show our method at work for a financial data set and explain differences between our copula-based approach and the classical approach. Our new method yielear models also.     

A body passes by: the flâneur and the senses in nineteenth-century London and Paris

Abstract

The flâneur is well-known for being the most emblematic nineteenth-century observer of urban life. Critics have often compared the flâneur to a camera eye which records everything and insisted on the predominance of sight over other senses in the cognitive process. This article emphasises the embodiedness of the flâneur’s vision, which is an experience of all the senses. Urban public space can be envisaged as a ‘metabolic space,’ in which “the links between background and figures are very unstable” (Augoyard 1991). The moving body of the flâneur, which can adapt to this changing space, seems to be in an ideal position to apprehend the metabolic body of the city. The flâneur is not only a “transparent eye-ball” (Emerson 2003), he is “a living eye” which communicates with all the other senses and captures the whole experience of moving through the city. By looking at texts by Balzac, Baudelaire, Dickens and Charlotte Brontë, the article shows that flânerie is a sensory activity that shapes our perception of the city as much as the city shapes our own flâneries by transforming our bodies into scribes who write the “thicks and thins of the urban text” (de Certeau, 1984).     

Population age structure and consumption growth: evidence from National Transfer Accounts

We assess the effects of the population age structure and the population dynamics on economic growth. Following recent research, we focus on the generational turnover effect to characterize the influence of birth and death rates, depending on the age profile of individual consumption, the extent of annuity market imperfections, and the willingness of households to shift consumption over time. Using data from the National Transfer Accounts on age profiles of consumption for a number of different countries, we assess—in a comparative way—the sign and the magnitude of the generational turnover effect and its impact on economic growth. We find considerable cross-country differences and trace them back to the underlying variation in demography and in the age structure of consumption.     

Routes to low mortality in poor countries revisited

In June 1986, Population and Development Review published a highly influential article by John Caldwell entitled “Routes to Low Mortality in Poor Countries.” Amid growing anxiety over decelerating world mortality decline, Caldwell explored social and political pathways to mortality success on the basis of two lists of superior mortality achievers and exceptionally poor mortality achievers, countries whose mortality rankings drastically differed from their income rankings. To mark the quarter-century since Caldwell's study and chart new pathways, this article looks at the subsequent performance of Caldwell's original exceptional achievers and develops an updated list of achievers. Analysis highlights the presence of many more poor achievers today; the rising importance of adult mortality as a marker of exceptional achievement; the increasing success of countries in Latin America and the Muslim world; the continued success of China, Vietnam, Cuba, and Costa Rica. dramatic improvements in schooling outcomes, particularly for women, have reduced the importance of education as a determinant of superior achievement. Reinforcing Caldwell's original assertions, the synthesis highlights how interactions between social consensus, health care systems, and human capital dependence offer a pathway to superior achievement. These forces may be especially powerful at moments of national crisis.     

Exact calculation of power and sample size in bioequivalence studies using two one‐sided tests

The number of subjects in a pharmacokinetic two‐period two‐treatment crossover bioequivalence study is typically small, most often less than 60. The most common approach to testing for bioequivalence is the two one‐sided tests procedure. No explicit mathematical formula for the power function in the context of the two one‐sided tests procedure exists in the statistical literature, although the exact power based on Owen's special case of bivariate noncentral t‐distribution has been tabulated and graphed. Several approximations have previously been published for the probability of rejection in the two one‐sided tests procedure for crossover bioequivalence studies. These approximations and associated sample size formulas are reviewed in this article and compared for various parameter combinations with exact power formulas derived here, which are computed analytically as univariate integrals and which have been validated by Monte Carlo simulations. The exact formulas for power and sample size are shown to improve markedly in realistic parameter settings over the previous approximations. Copyright © 2014 John Wiley & Sons, Ltd.     

Letter to the editor by the authors of Exact Calculation of Power and Sample Size in Bioequivalence Studies Using Two One‐sided Tests,Pharmaceutical Statistics,DOI: 10.1002/pst.1666

This article reflects the views of the authors and should not be construed to be those of the US Food and Drug Administration. Copyright © 2015 John Wiley & Sons, Ltd.     

Providing better protection and promoting growth: A defence of Averting the old age crisis

This article briefly summarizes the recommendations of the recent World Bank report, Averting the old age crisis , analyses why representatives of the ISSA and the ILO came to quite different policy conclusions from that report, and takes up other selected issues. The article argues that there are four underlying reasons for the divergence between the World Bank and the ILO/ISSA positions: the Bank is more concerned about the impact of social security systems on the broader economy; the Bank is troubled by the inequities that we often find in current systems in practice, even though they may look equitable on paper; the Bank believes that behavioural responses and political economy factors sometimes make non-viable the design changes of public systems recommended by the ILO and the ISSA; and the Bank places considerable emphasis on the benefits of risk diversification.