Solidarity in choosing a location on a cycle

We study the implications of two solidarity conditions on the efficient location of a public good on a cycle, when agents have single-peaked, symmetric preferences. Both conditions require that when circumstances change, the agents not responsible for the change should all be affected in the same direction: either they all gain or they all loose. The first condition, population-monotonicity, applies to arrival or departure of one agent. The second, replacement-domination, applies to changes in the preferences of one agent. Unfortunately, no Pareto-efficient solution satisfies any of these properties. However, if agents’ preferred points are restricted to the vertices of a small regular polygon inscribed in the circle, solutions exist. We characterize them as a class of efficient priority rules.     

On the construction of a class of efficient row-column designs

In this paper a method for the construction of a class of row-column designs with good statistical properties and high efficiency is presented. The class of designs produced is shown to exhibit balance, orthogonality and adjusted orthogonality. The efficiencies of these designs are investigated in detail, and they are shown to be very high, and possibly maximal in some cases.     

THE DIFFUSION OF MEDICAL TECHNOLOGY: SOCIAL NETWORK ANALYSIS AND POLICY RESEARCH

The purpose of this article is to demonstrate how social network analysis can be used to provide information for policy decisions pertaining to physicians' adoption and utilization of new medical technology. Interviews and hospital records were used to obtain data on refenals, consultations, discussions, and on-call coverage; utilization of a computer-based hospital information system; and personal and practice characteristics from 24 physicians who belong to a private group practice. The results of a block-model analysis suggest that the physician's relative position in the network is an important determinant of his/her participation in the diffusion process. A number of policy implications related to the introduction of new medical technology into practice settings are discussed.     

Moments of the sampled autocovariances and autocorrelations for a Gaussian white-noise process

Cumulants, moments about zero, and central moments are obtained for the mean-corrected serial covariances and serial correlations for series realizations of length n from a white-noise Gaussian process. All first and second moments (and some third, fourth, and higher moments) are given explicitly for the serial covariances; and the corresponding moments for the serial correlations are derived either explicitly or implicitly.     

Remarriage Among Divorced Persons in New Zealand

Trends in the remarriage of divorced persons in New Zealand since World War Two are examined with special attention to the period since 1968 during which the divorce rate has risen rapidly. While remarrying divorcees have formed increasing proportions of marriage cohorts since the late 1960s the remarriage rate, especially for females, has risen only because the divorced population has become more youthful. Comparison of the remarriage experience of synthetic divorce cohorts for 1961 and 1976 suggests that the likelihood of remarriage has fallen for both sexes where divorce occurs at ages below forty, but in particular for females divorced in their thirties.     

Outcomes assessment of role-play scenarios for teaching responsible conduct of research

We describe the summative assessment of role-play scenarios that we previously developed to teach central topics in the responsible conduct of research (RCR) to graduate students in science and engineering. Interviews with role-play participants, with participants in a case discussion training session, and with untrained students suggested that role-playing might promote a deeper appreciation of RCR by shifting the focus away from wanting to simply "know the rules." We also present the results of a think-aloud case analysis study and describe the development of a behaviorally-anchored rating scale (BARS) to assess participants' case analysis performance.     

The Effects of the Registration System on the Seasonality of Births: The Case of the Soviet Union

Scientists study seasonality in order to understand the effect of environmental, biological, and social factors on demographic events. Poor data quality can also affect seasonal variation in mortality and fertility statistics. The influence of error on seasonal data becomes crucial as researchers analyze timing and spacing of events in time-series analyses. In this study we examine the reported number of births by month in the Soviet Union for 1950, 1955, and 1958–85. The lowest number of births has typically occurred in December, and the highest in January. This seasonal pattern is not consistent with any plausible biological or behavioural explanation. It is probably an artifact of attributing births that actually occurred during the preceding December or earlier, to January. This implies that Soviet statistical practice has not followed the stated policy of attributing births to the period (day, month, year) in which they occur. A substantial reduction between the 1950s and 1985 in the December-January peak in reported births implies marked improvement in Soviet vital registration statistics. The Soviet case shows that characteristics of the registration system can impart a particular seasonal pattern to demographic data. It also shows that officially prescribed procedures are not always followed in data generation, even in centrally planned economies. Researchers should carefully examine the quality of seasonal data before concluding that the data reflect real variations in demographic behaviour.     

Consensual partnering in Australia: A review and 1991 census profile

This paper is the first part of a two-part examination of consensual partnering in Australia. It reviews the Australian literature on consensual partnering, summarizing evidence of its proliferation since the mid-1960s and also the findings of investigations into its nature and the personal attributes that predispose some people more than others to adopt it. It then discusses the shortcomings of Australian census data as a source for studying consensual unions, before using data from the 1991 Census to present the first elements in a comprehensive profile of the cohabiting population. These cover the basic demography of consensual partnering: the ages, marital statuses and family type distributions of those involved. The second author contributed to this paper while a student of Graduate Studies in Demography, The Australian National University. Views expressed are those of the authors, and are not necessarily those of the Australian Bureau of Statistics.     

Hypothesis Tests for Neyman's Bias in Case–Control Studies

Survival bias is a long recognized problem in case–control studies, and many varieties of bias can come under this umbrella term. We focus on one of them, termed Neyman's bias or ‘prevalence–incidence bias’. It occurs in case–control studies when exposure affects both disease and disease-induced mortality, and we give a formula for the observed, biased odds ratio under such conditions. We compare our result with previous investigations into this phenomenon and consider models under which this bias may or may not be important. Finally, we propose three hypothesis tests to identify when Neyman's bias may be present in case–control studies. We apply these tests to three data sets, one of stroke mortality, another of brain tumors, and the last of atrial fibrillation, and find some evidence of Neyman's bias in the former two cases, but not the last case.