Analytical representation of probabilities under the IAC condition

This paper extends the work of Gehrlein and Fishburn (1976) and Gehrlein (1982) by providing a general theorem relating to the analytical representation of the probability of an event in a given space of profiles. It applies to any event characterized by a set of linear inequalities regardless of whether the coefficients defining the inequalities are integer or fractional coefficients. An algorithm for the probability calculation is also suggested. This suggested methodology is used to provide a complete characterization of the vulnerability properties of the four scoring rules studied in Lepelley and Mbih (1994) to manipulation by coalitions in a 3-alternative n-agent society. Received: 21 October 1997/Accepted 19 November 1998     

An individual-based model for competingDrosophila populations

An individual-based model forDrosophila is formulated, based on competition amongst larvae consuming the same batch of food. The predictions of the model are supported by data for single speciesDrosophila populations reared in the laboratory. The model is used to build a simple discrete model for the dynamics ofDrosophila populations that are kept over a number of generations. The dynamics of a single species is shown to give either a stable equilibrium or fluctuations which can be periodic or chaotic. When the dynamics of a species in the absence of the other is periodic or chaotic, we found coexistence or two alternative states, on neither of which the species can coexist.     

The effects of child support guidelines: An analysis of the evidence in court records

Court records from four Ohio counties were used to compare child support orders before and after promulgation of federally mandated guidelines in 1987. There was no significant change in probability of Court Ordered Child Support. Amount Ordered in constant dollars increased between 1985 and 1987–88. Variables influencing Court Ordered Child Support differed post-guidelines. Years Married, Attorney for Both and Attorney for Wife were significant in both years. Number of Children, Rural, and Wife's Motions were significant in 1987–88. Variables affecting amount ordered also differed after adoption of the guidelines. Wife Contested, Husband's Motions, Defendant and Plaintiff no longer were significant in 1987–88. Years Married and Payment by Father were significantly related to Amount Ordered in 1985 but not in 1987–88. Number of Children, Expenses Paid, and Number of Assets were significantly related to Amount Ordered in both years.Salaries and research support were provided by state and federal appropriations to the Ohio Agricultural Research and Development Center, and by the Department of Family Resource Management, and The Office of Research and Graduate Studies, The Ohio State University.Kathryn Stafford is Associate Professor, Department of Family Resource Management, 1787 Neil Avenue, Columbus, OH 43210-1295. Her research interests include household management and time use. She received her Ph.D. from Cornell University.Golden Jackson is Assistant Professor, Department of Family Resource Management, 1787 Neil Avenue, Columbus, OH 43210-1295. Her research is primarily in the area of the economic effects of divorce. She received her Ph.D. from The Ohio State University.Sharon Seiling is Assistant Professor and Extension Specialist in Family Resource Management, Department of Family Resource Management, 1787 Neil Avenue, Columbus, OH 43210-1295. Her research is on the impact of family change, especially divorce, on access to housing and overall financial well-being. She received her Ph.D. from Cornell University.     

Does Family Structure Matter in the Relationships Between Youth Assets and Youth Alcohol,Drug and Tobacco Use?

This study investigated significant relationships between youth assets and youth alcohol, tobacco, and drug use that differ according to family structure (one- or two-parent households). Data were collected from a randomly sampled inner-city population (n=1,256 teenagers and 1,256 parents of the teenagers) using in-home, in-person interviews. Logistic regression analyses, stratifying by one- and two-parent household status, were conducted with nine youth assets as the independent variables and youth alcohol, tobacco, and drug use as the dependent variables. Results indicated that the associations between assets and risk behaviors varied depending upon whether the youth lived in one- or two-parent households. Continued research is warranted to further investigate associations among family structure, youth assets, and youth risk behaviors.     

Long range planning of paper and board supplies

Most standard textbooks identify three essential elements of effective corporate planning: an information input of appropriate depth, critical appraisal of the company's relative position and application of advanced evaluation techniques. Extension of the vision period, for long range or strategic planning, will unavoidably introduce further complexities into these constituent routines of corporate planning as well as into the strategic decision making process. The author reviews the long term outlook for paper and board suppliers and users and points out the strategic advantages of these basic materials.     

Safety culture: under-specified and overrated?

Is the measurement of 'safety culture' a valid management tool in the effort to reduce accident rate and improve safety performance, or is it a fuzzy academic concept, lacking empirical validation? The answer to this question seems to depend on whom one asks. The UK Health and Safety Commission has encouraged companies to improve their safety performance through the development of a 'positive safety culture'. However, academic discussions in this area suggest that the concept remains vague, lacks empirical validation and is used as an 'umbrella term' for all the social and organizational factors that affect accident rate. This paper reviews the existing literature on safety culture and provides some clarification in terms of definition, empirical evidence and theoretical development. A theoretical framework of the mechanisms by which safety culture affects safety behaviours in organizations is proposed. The implications for practical management issues are discussed and future challenges and areas for further research are identified.     

Gender-Specific Changes in Students' Sexual Behaviors and Attitudes at a Southeastern University between 1973 and 1988

Abstract

This study investigated the gender-specific, self-reported sexual behaviors and attitudes of never-married college students attending a southeastern university in 1973 and 1988. Data were collected by means of a mailed questionnaire that remained essentially unchanged for both years. The authors found that both men and women reported an increase in heterosexual relationships that included sexual intercourse and a decrease in nonsexual relationships with the other gender. The majority of the students perceived themselves as adequately informed about sexuality and satisfied with their relationships, although the proportion of men who reported being satisfied with their relationships declined over the 15 years. The students indicated that sexuality education should focus primarily on information about AIDS and on preparation for marriage.     

Social Fathers and Child Well‐Being

Many young children born to unwed parents currently live with their biological mothers and their mothers’ new partners (social fathers). This study uses data from the Fragile Families and Child Well‐Being Study (N = 1,350) to assess whether involvement by resident social fathers is as beneficial for child well‐being as involvement by resident biological fathers and whether the involvement of the child’s nonresident biological father alters the relationship between resident social father engagement and child outcomes. Results indicate that involvement by resident social fathers is as beneficial for child well‐being as involvement by resident biological fathers and that frequent contact with the child’s nonresident biological father does not diminish the positive association between residential social father involvement and child well‐being.