IMPACT OF SEAT BELT USE ON DRIVING BEHAVIOR

Previous research has indicated that individual compensating behavior, specifically, more risky driving may reduce the effectiveness of seat belt laws. We test the compensating-behavior hypothesis using individual-specific survey data. The analysis also incorporates individual risk tastes. Our results indicate that the compensating-behavior hypothesis applies only to those that are not strongly risk averse. Other risk-differentiated groups do not exhibit compensating behavior. Finally, it seems that individuals learn to reduce compensating behavior over time.     

Mexican American Parents' Involvement in Adolescents' Peer Relationships: Exploring the Role of Culture and Adolescents' Peer Experiences

This study examined the nature and correlates of Mexican American mothers' and fathers' involvement in adolescents' peer relationships along 4 dimensions: support, restriction, knowledge, and time spent with adolescents and peers. Mexican American adolescents and their parents in 220 families described their family relationships, cultural orientations/values, and experiences with adolescents' peers in home interviews. In addition, time-use data were collected during a series of 7 phone calls to measure parents' time spent with adolescents and peers and parents' knowledge of adolescents' daily experiences with peers. Multilevel models revealed connections between parents' involvement in adolescents' peer relationships and both parents' Mexican and Anglo orientations and familism values and adolescents' peer experiences (e.g., deviant peer affiliations, friends' ethnic orientation). Findings further revealed some evidence that parent and adolescent gender moderated the patterns, with mothers' (but not fathers') restrictions on peer relationships being associated with adolescents' deviant peer affiliations and parents placing greater restrictions on daughters' than on sons' peer relationships when they had more frequent deviant peer affiliations.     

Application of Geostatistics to Risk Assessment

Geostatistics offers two fundamental contributions to environmental contaminant exposure assessment: (1) a group of methods to quantitatively describe the spatial distribution of a pollutant and (2) the ability to improve estimates of the exposure point concentration by exploiting the geospatial information present in the data. The second contribution is particularly valuable when exposure estimates must be derived from small data sets, which is often the case in environmental risk assessment. This article addresses two topics related to the use of geostatistics in human and ecological risk assessments performed at hazardous waste sites: (1) the importance of assessing model assumptions when using geostatistics and (2) the use of geostatistics to improve estimates of the exposure point concentration (EPC) in the limited data scenario. The latter topic is approached here by comparing design-based estimators that are familiar to environmental risk assessors (e.g., Land's method) with geostatistics, a model-based estimator. In this report, we summarize the basics of spatial weighting of sample data, kriging, and geostatistical simulation. We then explore the two topics identified above in a case study, using soil lead concentration data from a Superfund site (a skeet and trap range). We also describe several areas where research is needed to advance the use of geostatistics in environmental risk assessment.     

Conflict Resolution Between Mexican Origin Adolescent Siblings

We investigated correlates of adolescents’ sibling conflict resolution strategies in 246, two‐parent Mexican origin families. Specifically, we examined links between siblings’ conflict resolution strategies and sibling dyad characteristics, siblings’ cultural orientations and values, and sibling relationship qualities. Data were gathered during home interviews with adolescent siblings. Older siblings were more likely to use controlling strategies whereas younger siblings were more likely to use nonconfrontation strategies. Cultural orientations and familism values were positively linked to siblings’ solution orientation. Solution orientation strategies were associated with sibling intimacy, and control strategies were related to sibling negativity. Discussion highlights the importance of considering the cultural context in which sibling relationships are embedded.     

An Experimental Comparison of Time-Based and Economic-Based Scheduling Methods to Maximize Net Present Value*

In the past, performance in dynamic-scheduling environments was primarily measured in terms of time or physical shop characteristics. Objectives such as mean tardiness, flow time, and work-in-process inventory were commonly used. Today, there is increasing interest in the use of more advanced economic performance measures. These measures have the more comprehensive objective of maximizing ownership wealth by economically scheduling jobs and tasks. This study presents a large-scale experiment testing time-based and economic-based scheduling methods in a dynamic job shop. These methods are evaluated on their ability to maximize net present value (NPV). The study considers the just-in-time (JIT) delivery environment. The job shop is hypothetical, but is based on models of real production situations. Results show that the use of very detailed economic information in a sophisticated manner generally improves economic performance. Where due dates are easy to achieve, however, time-based scheduling methods are at least as good as those based on economics. Also, where utilization is high and due dates tight, early cost information in release and dispatch is detrimental to schedule value.