Improving on truncated linear estimates of exponential and gamma scale parameters

We consider the problem of estimating the scale parameter of an exponential or a gamma distribution under squared error loss when the scale parameter θ is known to be greater than some fixed value θ₀. Natural estimators in this setting include truncated linear functions of the sufficient statistic. Such estimators are typically inadmissible, but explicit improvements seem difficult to find. Some are presented here. A particularly interesting finding is that estimators which are admissible in the untruncated problem which take values only in the interior of the truncated parameter space are found to be inadmissible for the truncated problem.     

Sustainable societies in the information age

This article interweaves the ideas of sustainable development, sustainable societies, and the power of advanced information technologies toward developing recommendations for social science research on information technology in society. Worldwide concern has arisen over the potentially catastrophic consequences of global climate and environmental change. As a result, sustainable development (i.e., the simultaneous protection of both the global environment and the global economy) is receiving considerable attention. Necessary for achieving sustainable development are sustainable societies, which are capable of designing, implementing, managing and evaluating long-term environmental programs. This article presents ten characteristics that describe sustainable societies and discusses how information technologies, from wireless personal digital assistants to intelligent agents to multi-media database systems, could support the evolution of sustainable societies. Topics for social science research related to designing and ameliorating the negative consequences of eight hypothetical computer-based systems are presented. Bruce E. Tonn is leader of the policy systems analysis group at Oak Ridge National Laboratory and co-principal investigator of the National Center for Environmental Decision-making Research. His research interests include environmental and energy policy, computers in society, decision making, and futures studies. He is past president of the Social Science Computing Association. His research focuses on planning, assessment and evaluation, energy use and conservation, and education.     

The estimation of Chilean mortality (1860-1940): limits and possibilities

The limitations and errors in data sources, primarily censuses and vital statistics, concerning mortality in Chile from 1865 to 1940 are examined. Solutions are offered to adjust the sources' underestimations, particularly with regard to infant mortality.     

Leslie matrix models

A review of the Leslie matrix model theory and its literature 1941-1987 is presented. The point of view is that of a mathematician who focuses on the parts of the theory which are relevant to demography. Works of a decidedly applied nature are not dealt with.     

Policies over time and pareto optimality

This paper is concerned with sequences of policies that occur over time in voting models and planning procedures. The framework for our analysis includes assumptions that are satisfied by models in the corresponding literatures, together with other standard assumptions for microeconomic analysis that involve time. The starting point for our analyses is the prespective that results from combining the following (widely held) views: 1) certain voting models and planning procedures can be interpreted as being non-tatonnement or sequential processes (where each policy in the sequence that is generated is actually experienced by voters or consumers) and 2) an alternative being Pareto optimal in any given period (temporal Pareto optimality) is the appropriate efficiency criterion only if the alternative is the final outcome from a tatonnement process-and that, otherwise, one should examine the efficiency of the entire path (using intertemporal Pareto optimality). Our first observation about the planning literature is that is has (by and large) neglected the efficiency criterion that is appropriate for the discrete-time procedures that can be interpreted as non-tatonnement or sequential processes-and that, what's more, such trajectories will (in general) fail to meet this criterion. Our second observation identifies some results that can be used to establish that some of these trajectories will at least be ultimately intertemporally Pareto optimal. In our discussion of voting theory, we review Buchanan's opposition to requiring (social) choice consistency for voting procedures-and his argument for this position on (Pareto) efficiency grounds. We then consider voting procedures that can be interpreted as non-tatonnement or sequential processes and arrive at the conclusion that, in these cases, (i) majority rule cycles are intertemporally Pareto inefficient and (ii) achieving intertemporal Pareto optimality requires choice consistency. We then go on to show that related observations apply to Kramer's normative conclusions about his dynamical model of political equilibrium — and identify some further references where similar observations apply. In the final part of our discussion of voting models, we arrive at the further conclusion that, in the most relevant cases, a trajectory that stays in the temporal Pareto set is not necessarily more desirable (on efficiency grounds) than one that doesn't.This paper has been improved by helpful comments and suggestions that have been provided by Kenneth Arrow, an anonymous referee, and the editor who handled the paper.Peter Coughlin gratefully acknowledges financial support provided by (i) National Science Foundation Grant No. SES-8409352, and (ii) the Center for Advanced Study in the Behavioral Sciences at Stanford (with support from National Science Foundation Grant No. BNS-8700864 and the Alfred P. Sloan Foundation).     

Ordinal utility models of decision making under uncertainty

This paper studies two models of rational behavior under uncertainty whose predictions are invariant under ordinal transformations of utility. The quantile utility model assumes that the agent maximizes some quantile of the distribution of utility. The utility mass model assumes maximization of the probability of obtaining an outcome whose utility is higher than some fixed critical value. Both models satisfy weak stochastic dominance. Lexicographic refinements satisfy strong dominance.The study of these utility models suggests a significant generalization of traditional ideas of riskiness and risk preference. We define one action to be riskier than another if the utility distribution of the latter crosses that of the former from below. The single crossing property is equivalent to a minmax spread of a random variable. With relative risk defined by the single crossing criterion, the risk preference of a quantile utility maximizer increases with the utility distribution quantile that he maximizes. The risk preference of a utility mass maximizer increases with his critical utility value.     

The effects of the age and structure of population on family change]

The age structure of a population is one basic factor of population research. It is not only affected by birth, death, immigration, and marriage, but it also reflected in changes of family size. The article analyzed it from two aspects: (1) the age structure of population acts on the size and structure of the family. The younger the age structure, the larger the family size. Otherwise, it is the opposite. According to the 1982 census, 35.4% of the population was 0-14 years in rural areas, and average family size was 4.6; but in urban areas 26.0% of the population was 0-14 years and family size was 3.9. The family was characterized as a nuclear family as industrialization in economic development increased and the population aged. In the 1982 census, 64.7% were nuclear family and 6% were aging population in China. Three- generation families (or more) have decreased dramatically. The change of family size and structure is affected by change of internal family age structure. The younger population (0-14 years) is dependent and 90% live with their parents. The adult population (15-59) years are more affected by marriage, birth and social economic action. Families are established in this age period and give much more effect to fertility. The aging population (over 60) years is facing changes. They appear to be a "Defect" family because the wife or husband has passed away. They change from independent to dependent. 78.3% population over 60 years were dependent on children or social welfare, only 21.7% were independent according to the survey in Beijing Changping County.     

Parents and patients: Members of an interdisciplinary team on an adolescent inpatient unit

In a six-year study on a locked psychiatric hospital unit for adolescents, first patients and then their families became integrated into the interdisciplinary treatment team. The results were universally beneficial. After initial resistance and some fine tuning of their skills, the staff became strong supporters of the program. Parents, no longer one down, developed a close working relationship with the therapists and milieu staff. Treatment planning and implementation was enriched by the interaction and dissension was minimized. Most important of all, the adolescents improved more rapidly and hospital stays were significantly shortened.     

Evidence for a common dissociative-like reaction among addicts

A questionnaire was designed to test selected aspects of the author's General Theory of Addictions (Jacobs, 1982). Data were collected from groups of compulsive gamblers, alcoholics, and compulsive overeaters, and compared with the responses to the same questionnaire obtained from normative samples of adolescents and adults. The more inclusive term, compulsive gambler, has been used throughout, since the sample of gamblers in this study included an inpatient subgroup who had been diagnosed as pathological gamblers, as well as a subgroup of Gamblers Anonymous members who had not been clinically evaluated. Findings support the author's theoretical position that, when indulging, different kinds of addicts will tend to share a common set of dissociativelike experiences that differentiate them from nonaddicts. This has been termed a state of altered identity.     

On estimating census undercount in small areas

"Net undercount rates in the U.S. decennial census have been steadily declining over the last several censuses. Differential undercounts among race groups and geographic areas, however, appear to persist. In the following, we examine and compare several methodologies for providing small area estimates of census coverage by constructing artificial populations. Measures of performance are also introduced to assess the various small area estimates. Synthetic estimation in combination with regression modelling provide the best results over the methods considered. Sampling error effects are also simulated. The results form the basis for determining coverage evaluation survey small area estimates of the 1900 decennial census."