DEPENDENCE AND INDEPENDENCE

The contributions that adult men and women make to households in terms of paid and unpaid work have undergone substantial change, particularly in respect of women's responsibility for income generation, and have been seen as part of the processes of individualization. Recent contributions to the literature have suggested that children are now acquiring independence earlier as part of those same processes. The paper uses qualitative methods to explore the way in which parents in two-parent families, where both are employed, perceive the risks attached to children's exercise of greater independence, how they seek to ‘manage’ those risks and how far the perceptions of parents accord with those of children. We find parents’ perceptions of risk to be strong, but to have little to do with working patterns. In addition, they are often at odds with the actual behaviour of the child. Risks are managed by negotiation, in which children played an active part. We are also able to make some preliminary comments on the difficulties of interpreting scale measures in relation to interview evidence.     

Assessing the cumulative effects of stress: The association between job stress and allostatic load in a large sample of Chinese employees

Job stress can lead to various system dysfunctions, but until now no reliable biomarkers for its assessment have been identified. Allostatic load (AL) is an index that enables the cumulative effect on the body of chronic stress to be assessed, and is derived from a set of relevant biological measures. In this study, a 13-parameter index (building on the original 10-item index) was used to examine the relationship between job strain and AL. Participants were 1219 healthy Chinese employees. Job strain was measured using the Job Content Questionnaire, and AL was assessed by various possible stress responses, including blood pressure, cholesterol, indicators of glucose metabolism, and hormone and inflammation markers. AL in the high job strain group differed sharply from that in the low job strain group. The AL score was positively associated with age and educational level. Several individual parameters also differed between the two groups. Men scored significantly higher on AL and cardiovascular and metabolic health outcomes, whereas for women the associations appeared in the biological indicators. Analyses indicated that decision latitude (DL) and job demands were significantly related to AL. Job demands correlated significantly with the primary biological indicators and DL with the secondary health outcomes. In conclusion, this study provides evidence of the value of measuring allostatic load in assessing the chronic effects of job stress.     

A Simple Formula for Calculating the "Mass Density" of a Lognormally Distributed Characteristic: Applications to Risk Analysis

Statements such as "80% of the employees do 20% of the work" or "the richest 1% of society controls 10% of its assets" are commonly used to describe the distribution or concentration of a variable characteristic within a population. Analogous statements can be constructed to reflect the relationship between probability and concentration for unvarying quantities surrounded by uncertainty. Both kinds of statements represent specific usages of a general relationship, the "mass density function," that is not widely exploited in risk analysis and management. This paper derives a simple formula for the mass density function when the uncertainty and/or the variability in a quantity is lognormally distributed; the formula gives the risk analyst an exact, "back-of-the-envelope" method for determining the fraction of the total amount of a quantity contained within any portion of its distribution. For example, if exposures to a toxicant are lognormally distributed with σ_{in x}= 2, 50% of all the exposure is borne by the 2.3% of persons most heavily exposed. Implications of this formula for various issues in risk assessment are explored, including: (1) the marginal benefits of risk reduction; (2) distributional equity and risk perception; (3) accurate confidence intervals for the population mean when a limited set of data is available; (4) the possible biases introduced by the uncritical assumption that extreme "outliers" exist; and (5) the calculation of the value of new information.     

Corporate Transformation to the Multilayered Subsidiary Form: Changing Economic Conditions and State Business Policy

Despite the prevalence of corporate change in the last decade, researchers have not examined whether a change occurred in the corporate form. The analysis here presents a historical case study of a large U.S. corporation and quantitative data on the largest 100 U.S. industrial corporations. The case study examines the effects of changing economic conditions and state business policy on the corporate form. This study demonstrates that the corporation changed to a multilayered subsidiary form (MLSF): a corporation with a hierarchy of two or more levels of subsidiary corporations with a parent company at the top of the hierarchy operating as a management company. Whereas rising debt and increasing competition in the 1970s and 1980s undermined corporations' capacity to accumulate capital, changes in state business policy in the mid-1980s provided the political-legal structure for corporations to restructure their assets as subsidiary corporations tax free. Changes in state business policy also provided a means for corporations to merge, acquire, and spin-off subsidiary corporations tax free. Quantitative data on the 100 largest U.S. industrial corporations show that while the multidivisional form decreased, the MLSF increased between 1981 and 1993. Findings support a capital dependence framework. The MLSF constructs liability firewalls among corporate entities and creates internal capital markets, reducing dependence on external capital markets.     

Multiobjective Decision-Tree Analysis1

Single-objective-based decision-tree analysis has been extensively and successfully used in numerous decision-making problems since its formal introduction by Howard Raiffa more than two decades ago. This paper extends the traditional methodology to incorporate multiple noncommensurate objective functions and use of the conditional expected value of the risk of extreme and catastrophic events. The proposed methodology considers the cases where (a) a finite number of actions are available at each decision node and (b) discrete or continuous states of nature can be presented at each chance node. The proposed extension of decision-tree analysis is introduced through an example problem that leads the reader step-by-step into the methodological procedure. The example problem builds on flood warning systems. Two noncommensurate objectives—the loss of lives and the loss of property (including monetary costs of the flood warning system)–are incorporated into the decision tree. In addition, two risk measures—the common expected value and the conditional expected value of extreme and catastrophic events—are quantified and are also incorporated into the decision-making process. Theoretical difficulties associated with the stage-wise calculation of conditional expected values are identified and certain simplifying assumptions are made for computational tractibility. In particular, it is revealed that decisions concerning experimentation have a very interesting impact on the noninferior solution set of options—a phenomenon that has no equivalence in the single-objective case.     

Cellular telephones and motor-vehicle collisions: Some variations on matched-pairs analysis

We describe the analysis of some matched-pair binary data arising from a study designed to investigate whether cellular-telephone use is associated with motor-vehicle collisions. Conditional and random effects approaches to the problem are derived and compared. Driving intermittency is a potential confounder whose effect is assessed by strategic choices of the control period and by application of the bootstrap. The marked discrepancy between the conditional and random approaches merits further study.     

The Effect of Risk Beliefs on Property Values: A Case Study of a Hazardous Waste Site1

Health risk beliefs of homeowners near a landfill site were assessed in a survey and compared to expert judgments of the health risks of living near the site. A bimodal distribution of health risk beliefs suggested sharp disagreement between the experts and at least some of the residents. Correlates of high risk beliefs included perception of odor from the site, exposure to media coverage of the problem, having children living at home, age (younger respondents more concerned), and gender (females more concerned). An aggregated neighborhood health risk belief predicted reductions in home prices even after controlling for home physical characteristics, such as size and other disamenities such as proximity to a freeway. In the 4100 homes near the site, the estimated depression in property values was estimated to total about $40.2 million before the site was closed and to be about $19.7 million after closure. Implications of these results for community conflict and for benefit-cost analysis of hazard site remediation are discussed.     

Major Hazard Information Policy in the European Community: Implications for Risk Analysis

The main impetus to the development of information about major industrial hazards in the European Community comes from the so-called Seveso Directive, which defines an information network and requires the generation and transmission of information as the basis for accident prevention and risk management. This important policy development, which calls for the formal identification and analysis of major hazards and the communication of risk information to members of the public, presents new opportunities and challenges to risk analysis and research in Europe. This paper briefly reviews the accidents that gave rise to the Directive and shaped its content, and then summarizes its requirements. The status of its implementation in the EC Member States is discussed, with special emphasis given to the comparison of safety analysis practices, the Major Accident Reporting System (MARS), and risk communication. Some new research directions stimulated by the Directive are identified.     

Entropy Principles in Decision Making Under Risk

This paper considers decision problems where: (1) The exact probability distribution over the states of nature is not precisely known, but certain prior information is available about the possibilities of these outcomes; (2) A prior distribution over the states of nature is known, but new constraint information about the probabilities becomes available. The maximum entropy principle asserts that the probability distribution with maximum entropy, satisfying the prior knowledge, should be used in the decision problem. The minimum cross-entropy principle says that the posterior distribution is the one which minimizes cross-entropy, subject to the new constraint information. The entropy principles have not gone uncriticized, and this literature, together with that justifying the principles, is surveyed. Both principles are illustrated in a number of situations where the distribution is either discrete or continuous. The discrete distribution case with prior interval estimates based on expert opinions is considered in detail.     

Life Years Lost at Hazardous Waste Sites: Remediation Worker Fatalities vs. Cancer Deaths to Nearby Residents

We present a hypothetical case study using the Years of Potential Life Lost (YPLL) metric to compare cancer risks incurred by residents living near a Superfund site to occupational fatality risks incurred by workers employed in that site's remediation. Since cancer occurs late in life, and because we assume its mortality rate is 60%, each case results in 8.8 YPLL. Each occupational fatality, which typically occurs earlier in life, results in 38.1 YPLL. In our case study, the residential population of 5000 incurred 1.3 YPLL, compared to 5.7 YPLL incurred by the 500 workers. Several uncertain assumptions may influence our calculations; moreover, occupational risks may be viewed as more "voluntary" than risks incurred by residents. However, because the magnitude of the YPLL incurred by workers and residents may be comparable, risk managers should consider occupational risks when evaluating remedial alternatives.