Comparison of three estimators of the number of species

We consider estimation of the number of cells in a multinomial distribution. This is one version of the species problem: there are many applications, such as the estimation of the number of unobserved species of animals; estimation of vocabulary size, etc. We describe the results of a simulation comparison of three principal frequent-ist' procedures for estimating the number of cells (or species). The first procedure postulates a functional form for the cell probabilities; the second procedure approxi mates the distribution of the probabilities by a parametric probability density function; and the third procedure is based on an estimate of the sample coverage, i.e. the sum of the probabilities of the observed cells. Among the procedures studied, we find that the third (non-parametric) method is globally preferable; the second (functional parametric) method cannot be recommended; and that, when based on the inverse Gaussian density, the first method is competitive in some cases with the third method. We also discuss Sichel's recent generalized inverse Gaussian-based procedure which, with some refine ment, promises to perform at least as well as the non-parametric method in all cases.     

Rebates, inventories, and intertemporal price discrimination

We demonstrate that universally redeemed rebates can increase manufacturer profits by reducing the incentives of downstream retailers to hoard inventories when optimal wholesale prices vary predictably over time. By bypassing retailers and making direct contracts with buyers, the manufacturer can increase the variations in effective prices paid by consumers without concomitantly creating larger incentives for retailers to hold inventories. During profitable, high-demand periods, manufacturer revenues are ordinarily constrained by'competition'from retailer inventories, thus limiting profits. However, by selectively offering rebates to consumers while maintaining high wholesale prices, low-demand periods can be accommodated without inducing retailer hoarding.     

Measuring the Dynamics of Interactional Synchrony

Past research has revealed that natural social interactions contain interactional synchrony. The present study describes new methods for measuring interactional synchrony in natural interactions and evaluates whether the behavioral synchronization involved in social interactions is similar to dynamical synchronization found generically in nature. Two methodologies, a rater-coding method and a computational video image method, were used to provide time series representations of the movements of the co-actors as they enacted a series of jokes (i.e., knock?Cknock jokes). Cross-spectral and relative phase analyses of these time series revealed that speakers?? and listeners?? movements contained rhythms that were not only correlated in time but also exhibited phase synchronization. These results suggest that computational advances in video and time series analysis have greatly enhanced our ability to measure interactional synchrony in natural interactions. Moreover, the dynamical synchronization in these natural interactions is commensurate with that found in more stereotyped tasks, suggesting that similar organizational processes constrain bodily activity in natural social interactions and, hence, have implications for the understanding of joint action generally.     

Exporting Brotherhood: Orangeism in South Australia

The idea of fraternity, and how to organise it, was one of nineteenth-century Europe's invisible exports to the New World. This paper explores the international diffusion of the Loyal Orange Institution, with comparative reference to Freemasonry, its main model. Three alternative explanations are discussed for its appeal outside Ireland (that it facilitated the assimilation of emigrants, transmitted ‘tribal’ Irish animosities to fresh contexts, or adapted itself to pre-existing sectarian rivalries abroad). These hypotheses are tested used evidence from South Australia, where Orangeism flourished in the absence of heavy Ulster immigration. A collective profile of Orange South Australia is derived from Lodge records showing age, religious denomination and occupation, and the appeal of Orangeism is related to local political and religious contexts. In this case at least, Orangeism was primarily an export of organisational techniques rather than of Irish personnel or Irish bigotry.     

Causality in Contemporary American Sociology: An Empirical Assessment and Critique

Using a unique data set of causal usage drawn from research articles published between 2006–2008 in the American Journal of Sociology and American Sociological Review, this article offers an empirical assessment of causality in American sociology. Testing various aspects of what we consider the conventional wisdom on causality in the discipline, we find that (1) “variablistic” or “covering law” models are not the dominant way of making causal claims, (2) research methods affect but do not determine causal usage, and (3) the use of explicit causal language and the concept of “mechanisms” to make causal claims is limited. Instead, we find that metaphors and metaphoric reasoning are fundamental for causal claims‐making in the discipline. On this basis, we define three dominant causal types used in sociology today, which we label the Probabilistic, Initiating and Conditioning types. We theorize this outcome as demonstrating the primary role that cognitive models play in providing inference‐rich metaphors that allow sociologists to map causal relationships on to empirical processes.     

LIFE CHANCES AND CHOICES:

A Weberian lifestyles approach is employed to examine differences in quality of life among the homeless. Using a systematic random sample of 161 homeless people in a mid-sized, Southern metropolitan area, the study focuses on the impact of life chances and social choices on aspects of quality of life in this severely challenged population. Regression results show that a number of life chance and social choice variables affect general and domain-specific well-being. While chances and choices both contribute to these aspects of quality of life, there is only modest evidence of a mediating effect. With the exception of depressive symptoms, life chances appear to play a more important role in quality of life differences than life choices. The specific life chance and choice factors influencing aspects of quality of life vary with each separate well-being outcome. The implications of these findings for general sociology and homeless social policy are explored.