Mark-resighting analysis of a California gull population

California gulls ( Larus californicus ) of known age and sex were censused on their breeding colony in 1979, 1980 and 1984 through 1993. Ages of 235 males and 196 females ranged from 4 to 27 years. Age classes used in the analysis were limited to 17, 4 through 19, and 20 or more as a final age category because data on gulls over 20 were sparse. Survival declined with age in a way that was parsimoniously modelled with a quadratic function. Other factors, sex and time, did not explain any variation in survival. Resighting depended on age, sex and time. Younger adults skipped breeding more frequently than did older adults, and females skipped breeding more frequently than did males. There was also good evidence for time dependence in resighting probability, but its inclusion in the model occurred at the expense of interpretability and precision. In a data set such as this, resighting probability may assume more importance than a mere 'nuisance parameter'. In this study, resighting history measured attendance at the breeding ground. In turn, attendance rates may be a manifestation of reproductive strategy, which can also have consequences for survival. In this situation, there may be heterogeneity in both survival and resighting probability that is unexplained by the model. While such complexity may well be a nuisance to deal with, it can also point to important biological questions.     

Evaluating the slavonian census of 1698 part II: A microsimulation test and extension of the evidence

An adjusted 17th C. census based on critical reading of the historical text is the basis for indirect estimation of uncounted persons. The census states no ages and excludes many categories of household residents. Microsimulation based on historically and ethnographically plausible rates and household formation scenarios produces simulated households that match the observable portions of households in the adjusted census. Microsimulation results permit estimation of the uncounted population, of the kinship and age composition of households under extant frontier conditions, and the probable future composition of households as the frontier stabilized and land shortage began to exert pressure for greater density and household complexity.     

Productivity indices and survival rate estimates from MAPS,a continent-wide programme of constant-effort mist-netting in North America

The Monitoring Avian Productivity and Survivorship (MAPS) programme is a cooperative effort to provide annual regional indices of adult population size and post-fledging productivity and estimates of adult survival rates from data pooled from a network of constant-effort mist-netting stations across North America. This paper provides an overview of the field and analytical methods currently employed by MAPS, a discussion of the assumptions underlying the use of these techniques, and a discussion of the validity of some of these assumptions based on data gathered during the first 5 years (1989-1993) of the programme, during which time it grew from 17 to 227 stations. Ageand species-specific differences in dispersal characteristics are important factors affecting the usefulness of the indices of adult population size and productivity derived from MAPS data. The presence of transients, heterogeneous capture probabilities among stations, and the large sample sizes required by models to deal effectively with these two considerations are important factors affecting the accuracy and precision of survival rate estimates derived from MAPS data. Important results from the first 5 years of MAPS are: (1) indices of adult population size derived from MAPS mist-netting data correlated well with analogous indices derived from point-count data collected at MAPS stations; (2) annual changes in productivity indices generated by MAPS were similar to analogous changes documented by direct nest monitoring and were generally as expected when compared to annual changes in weather during the breeding season; and (3) a model using between-year recaptures in Cormack-Jolly-Seber (CJS) mark-recapture analyses to estimate the proportion of residents among unmarked birds was found, for most tropical-wintering species sampled, to provide a better fit with the available data and more realistic and precise estimates of annual survival rates of resident birds than did standard CJS mark-recapture analyses. A detailed review of the statistical characteristics of MAPS data and a thorough evaluation of the field and analytical methods used in the MAPS programme are currently under way.     

Ethical dilemmas in social problems research: A theoretical framework

Interest in ethical issues in social science has increased greatly in recent years. However, no comprehensive framework for the prediction and elimination of ethical dilemmas has been presented in the literature. This paper first analyzes reasons for increased interest in ethical issues, and then presents a broad framework for prediction and analysis of ethical problems. This framework is based on exchange theory, and shows the interdependencies between five “publics” in the research process: sponsors, researchers, subjects, the media, and the general public. The model also utilizes the sociological concepts of role of each public, the configuration of ascribed and achieved status, and norm abeyance. The primary exchange concepts used are cost, benefit, and trust. The model is illustrated with four actual research projects where ethical dilemmas occurred, and is found to be predictive of ethical problems if there are great disparities in cost/benefit ratios between subjects and researchers or sponsors, if there is great discrepancy between the status of the subjects and the researchers or sponsors, and if the researchers engage in norm abeyance. the author ofMethods of Social Research and numerous articles on research methods. Bailey also is interested in theory and ecology. This research was partially funded by UCLA Senate Research Committee Grant #2884.     

Shifting boundaries: Doing social science in the 1990s—A personal odyssey

Drawing on my own 40 years as a social scientist, I argue, as have others in recent years, that rather than a contaminant, one's own biography can be a useful tool in social analysis. I place my personal struggle with this issue in a larger cultural context and point to a shift in the boundaries between public and private, which has profound implications for the way we teach, write, and do research.Presidential address delivered at the Eastern Sociological Society Annual Meetings, Baltimore, Maryland, March 19, 1994.     

A Dynamic Model of Investment in the U.S. Beef-Cattle Industry

Reproduction constraints lead to some a priori information that may prove valuable in econo- metrically modeling inventory dynamics within the U.S. cattle herd. The distributed-lag models estimated for animal inventories suggest an implicit incorporation of the age distribution of the herd that is crucial to understanding the retention/culling (investment) decisions. The estimated equations are validated using post-sample observations that were withheld prior to estimation. The final-form dynamic equations have complex roots and protracted price and investment effects. The parameter estimates are used to calculate intermediate and long-run elasticities at the means of relevant variables.     

Hassles,hardiness and absenteeism: Results of a 3-year longitudinal study

Abstract

In this 3-year longitudinal study of 229 full-time employees, the authors investigated the association between hassles, two measures of personality hardiness, and absenteeism verified from medical personnel records and self-reported hospitalization owing to injury and illness. Using stepwise multiple regression analysis, hassles, but neither of the hardiness measures, significantly predicted absenteeism when controlling for psychological well-being and relevent demographic variables over the 3-year period. The alternative measure of hardiness, but not any of the original Kobasa personality hardiness scales, predicted self-reported hospitalization for injury and illness. Little evidence for the predicitve validity of the Kobasa personality hardiness components, or composite hardiness score, existed for either absenteeism or self-reported hospitalization in this study. These findings support the concept that the current conceptualization, measurement and use of the original Kobasa hardiness scales should be re-evaluated.     

Gender and Cultural Adaptation in Immigrant Families

The study of immigration and immigrants' experiences benefits from examining the contribution of gender. In this article, we focus on the importance of gender for understanding different aspects of family functioning. Conditions associated with immigration and settlement in the receiving society may challenge expectations about gender-related roles, resulting in the renegotiation of these roles in immigrant families. Also, there is evidence of different socialization demands on daughters compared to sons in immigrant families, a difference that has potential implications not only for parent-child relationships, but also for the development of ethnocultural identity among adolescents and young adults.     

A Poisson-multinomial mixture approach to grouped and right-censored counts

Although count data are often collected in social, psychological, and epidemiological surveys in grouped and right-censored categories, there is a lack of statistical methods simultaneously taking both grouping and right-censoring into account. In this research, we propose a new generalized Poisson-multinomial mixture approach to model grouped and right-censored (GRC) count data. Based on a mixed Poisson-multinomial process for conceptualizing grouped and right-censored count data, we prove that the new maximum-likelihood estimator (MLE-GRC) is consistent and asymptotically normally distributed for both Poisson and zero-inflated Poisson models. The use of the MLE-GRC, implemented in an R function, is illustrated by both statistical simulation and empirical examples. This research provides a tool for epidemiologists to estimate incidence from grouped and right-censored count data and lays a foundation for regression analyses of such data structure.