ORDER SELECTION IN ARMA MODELS USING THE FOCUSED INFORMATION CRITERION

This paper develops a new approach for order selection in autoregressive moving average models using the focused information criterion. This criterion minimizes the asymptotic mean squared error of the estimator of a parameter of interest. Simulation studies indicate that the suggested criterion is quite effective and comparable to the Akaike information criterion, the corrected Akaike information criterion and the Bayesian information criterion in autoregressive moving average order selection. The use of the focused information criterion for the simultaneous selection of regression variables and order of the error process in a linear regression model with autoregressive moving average errors is also considered.     

Marriages of bisexual men

This study examined the marriages of 26 couples in which the husband was bisexual. The subjects were a non-clinical sample married for at least two years and intending to continue their marriages. The sample was, overall, highly educated and earned concomitantly high incomes. Subjects were administered the Klein Sexual Orientation Grid and a research questionnaire to determine successful or problematic aspects of their marriages. Subjects were, for the most part, satisfied with the quality of their marriages, sexually active within the marriages, and open about the husband's homosexual behavior. A high-level of sexual activity within the marriage, open and direct communication, a valued friendship, previous counseling or psychotherapy, cognitive flexibility, and financial independence contributed to the success of these marriages. The husbands reported a great deal of ambiguity about their homosexual behavior, and the couples reported intense conflict dealing with their open marriage styles.     

Acceleration of the Multiple-Try Metropolis algorithm using antithetic and stratified sampling

The Multiple-Try Metropolis is a recent extension of the Metropolis algorithm in which the next state of the chain is selected among a set of proposals. We propose a modification of the Multiple-Try Metropolis algorithm which allows for the use of correlated proposals, particularly antithetic and stratified proposals. The method is particularly useful for random walk Metropolis in high dimensional spaces and can be used easily when the proposal distribution is Gaussian. We explore the use of quasi Monte Carlo (QMC) methods to generate highly stratified samples. A series of examples is presented to evaluate the potential of the method.     

A review of image-warping methods

SUMMARY Image warping is a transformation which maps all positions in one image plane to positions in a second plane. It arises in many image analysis problems, whether in order to remove optical distortions introduced by a camera or a particular viewing perspective, to register an image with a map or template, or to align two or more images. The choice of warp is a compromise between a smooth distortion and one which achieves a good match. Smoothness can be ensured by assuming a parametric form for the warp or by constraining it using differential equations. Matching can be specified by points to be brought into alignment, by local measures of correlation between images, or by the coincidence of edges. Parametric and non-parametric approaches to warping, and matching criteria, are reviewed.     

The Evolution of Organizations: Suggestions from Complexity Theory About the Interplay Between Natural Selection and Adaptation

There has been much debate in the managementliterature between neo-Darwinists (who believe in thenatural selection of populations of organizations) andadaptationists (who contend that changes in organization structure and behavior occur in response to theenvironment). The general thesis of neo-Darwinism isthat species are blindly selected for survival by theenvironment. The latest empirical support for the dominant neo-Darwinism perspective adopted bymost biologists is based primarily on the experimentsconducted by Salvador Luria who claims to haveconclusively demonstrated that genes mutate randomly.Recently, however, biologists have re-examined Luria sresearch methods and, after replications of hisexperiments, now question some aspects of the validityof his results. Moreover, there is now new researchwhich provides support for the earlier adaptationistposition, namely, the existence of evolutionary driversand directors existing within self-organizing systems.Of particular importance to the present study is the experimental indication thatself-organizing systems play a conscious role in theirown evolution. We propose that similar mechanisms orprocesses operate in organizational adaptation, thuspointing toward a theoretical modification ofneo-Darwinism that embraces both adaptation and naturalselection in a general, unified theory.     

Reflections on facilitating a participatory community self-evaluation

This paper is a reflective essay about our experience in conducting a participatory, community self-evaluation of a neighborhood revitalization effort in Milwaukee, Wisconsin. We took a controversial approach to evaluation by focusing on learning community dialogues as a vehicle for program evaluation. As we implemented our strategy, two sets of contradictions surfaced. The first points to the fundamental differences between conventional and constructivist research paradigms. The second centers around our focus on dialogue as a strategy for evaluation. In response to these contradictions we performed three complementary roles: program evaluator, process consultant, and learning facilitator. We are not implying that we performed an outstanding job in these roles. Rather, this article is our way of taking stock of what we learned about our practice as evaluators and how we may expand our repertoire of skills in the future.     

Voting in professional associations: The case of the American sociological association revisited

Who votes in ASA elections? This article examines data on voter turnout from two recent presidential contests of the American Sociological Association in an analysis of the determinants of election participation. Extending the 1981 Ridgeway and Moore study of voting dynamics in the ASA, we hypothesize that intraorganizational networks and particular demongraphic characteristics link ASA members to the discipline in a manner analogous to the way such factors operate in the national electorate. On the basis of data compiled from 1985 and 1986 ASA election returns, we find that network factors are the most salient determinants of voting behavior. We conclude that those organizational ties that effectively link members, however directly or indirectly, to the larger Association are the most predictive of propensity to vote.     

Mixed effectivity and the essence of stability

Effectivity functions (EFs) are models of coalitional power. An EF is said to be stable when its core is nonempty irrespective of player preferences. When the outcome space is composed of lotteries, each player's indifference map will be a family of parallel hyperplanes. By explicitly recognizing this fact, we are able to attain much sharper stability results than found using traditional infinite EF theory. Frequently the inherent nature of cooperative problems imposes further restrictions on the domain of admissible preferences. Results are further refined by incorporating these restrictions into concepts relating to stability. A number of applications are also presented, including a study of pure exchange in the EF framework.The author is very grateful to two anonymous referees whose suggestions greatly improved the quality of this paper. Errors or shortcomings are the sole responsibility of the author.     

Continuous-Time Stochastic Processes with Cyclical Long-Range Dependence

This paper introduces continuous‐time random processes whose spectral density is unbounded at some non‐zero frequencies. The discretized versions of these processes have asymptotic properties similar to those of discrete‐time Gegenbauer processes. The paper presents some properties of the covariance function and spectral density as well as a theory of statistical estimation of the mean and covariance function of such processes. Some directions for further generalizations of the results are indicated.     

Do close parent-child relations reduce the mortality risk of older parents?

This analysis examines the association between affectional solidarity in older parent-child relationships, and the parents' length of survival over a 14-year interval. It is hypothesized that close intergenerational relations have the capacity to reduce pathogenic stress among elderly parents, thereby enhancing their ability to survive. Direct and buffering effects of affectional solidarity, as expressed by 439 elderly parents, are tested using data from the U.S.C. Longitudinal Study of Generations collected between 1971 and 1985. Buffering effects are examined in the context of social decline and social loss experienced by the older parent. Hazard regression models indicate that greater intergenerational affect increases survival time among parents who experienced a loss in their social network, particularly among those who were widowed less than five years. Neither a direct effect of affection nor a buffering effect in the presence of social decline were found. It is concluded that the mortal health risks associated with the stress of being widowed can be partially offset by affectionate relations with adult children.