Gatekeeper's response: A rejoinder

Gender, marital status, age, and race were considered in relation to the amount and assessment of social ties among 1,124 unmarried men and women aged 40 and over. When there were significant effects of marital status, widowed people tended to be advantaged in amount and supportiveness of their informal ties, although the influence of marital status was affected by age and race. Contrary to some literature, gender differences in social relationships favoring women were not consistently observed. The oldest never married may have the greatest potential needs for affective and instrumental support.     

Generating Probabilistic Spatially-Explicit Individual and Population Exposure Estimates for Ecological Risk Assessments

Exposure to chemical contaminants in various media must be estimated when performing ecological risk assessments. Exposure estimates are often based on the 95th-percentile upper confidence limit on the mean concentration of all samples, calculated without regard to critical ecological and spatial information about the relative relationship of receptors, their habitats, and contaminants. This practice produces exposure estimates that are potentially unrepresentative of the ecology of the receptor. This article proposes a habitat area and quality-conditioned exposure estimator, E[HQ], that requires consideration of these relationships. It describes a spatially explicit ecological exposure model to facilitate calculation of E[HQ]. The model provides (1) a flexible platform for investigating the effect of changes in habitat area, habitat quality, foraging area, and population size on exposure estimates, and (2) a tool for calculating E[HQ] for use in actual risk assessments. The inner loop of a Visual Basic program randomly walks a receptor over a multicelled landscape--each cell of which contains values for cell area, habitat area, habitat quality, and concentration--accumulating an exposure estimate until the total area foraged is less than or equal to a given foraging area. An outer loop then steps through foraging areas of increasing size. This program is iterated by Monte Carlo software, with the number of iterations representing the population size. Results indicate that (1) any single estimator may over- or underestimate exposure, depending on foraging strategy and spatial relationships of habitat and contamination, and (2) changes in exposure estimates in response to changes in foraging and habitat area are not linear.     

Short notices

Howard M. Gitelman, Workingmen of Waltham: Mobility in American Urban Industrial Development, 1850–1890 (1975), xvi+192 (Johns Hopkins University Press: Baltimore and London, £5.50).

Michael J. Cullen, The Statistical Movement in Early Victorian Britain. The Foundations of Empirical Social Research (1975), xii+205 (Harvester Press, Hassocks, £7.50).

Raymond Wolters, The New negro on Campus: Black College Rebellions of the 1920s (1975), viii+370 (Princeton University Press, £7.90).

Marie B. Rowlands, Masters and Men in the West Midland Metalware Trades before the Industrial Revolution (1975) x+198 (Manchester University Press, Manchester, £8.00).

Dwight L. Smith (ed.), Afro‐American History: A Bibliography (1974), xvi+856 (ABC Clio Inc., Santa Barbara and Oxford, £22.50).

Hugh Cunningham, The Volunteer Force: a Social and Political History 1859–1908 (1975) 168 (Croom Helm, £6.50).

Leslie Clarkson, Death, Disease and Famine in Pre‐Industrial England (Dublin, 1975), iii+188 (Gill and Macmillan, £8.75).

Arnold J. Bauer, Chilean Rural Society front the Spanish Conquest to 1930 (1975), xviii+265 (Cambridge University Press, Cambridge, £7.90).

R. Kieckhefer, European Witch Trials: Their Foundation in Popular and Learned Culture, 1300–1500 (1976), x+181 (Routledge and Kegan Paul, £5.25).

David Elliston Allen, The Naturalist in Britain: a Social History (1976), xii+292 (Allen Lane, £9.00).

Paul Smith (ed.), The Historian and Film (1976), viii+208 (Cambridge University Press, £4.95).

Katherine S. Naughton, The Geentry of Bedfordshire in the 13th and 14th ceaturies (1976), 90 (Leicester University Press, Leicester, Local History Occ. Papers. 3rd series, No. 2. £3.75).

Thomas J. Archdeacon, New York City, 1664–1710: Conquest and Change (1976), 197 (Cornell University Press, Ithaca and London, £6.35).     

Shylock is not Heartless: The Function of Separation in Men's Emotional Development

‘Shylock is not Heartless’ uses poetry, film and the popular press to illustrate men's adherence to the traditional male tasks of protector and provider. Some men shift from protector and provider to the negative equivalent, controller and possessor, at the crisis point of separation. For others, separation provides the impetus for a journey inward toward self. The metaphor of the Iceberg and the Ocean has been found useful in helping some men observe the differences between them and their female partners.     

Organisational buying behaviour in changing times

In a recent paper, Johnston and Lewin (1996) analyse the stream of research on organisational buyer behaviour published over the past 25 to 30 years isolating eight propositions which they encapsulate in their ‘Risk Continuum'. Our paper, reports a comparison between Johnston and Lewin's analysis of the extant literature and current buying practices as revealed by interviews with senior UK buyers. We found that business practice has changed in the intervening years. New, process-driven management styles are changing the way in which UK buyers and suppliers interact, yet work reflecting this change (by, for instance, the European based IMP Group) is under-represented in textbooks and teaching. We question the continuing predominance of the established risk management view of organisational buyer behaviour based upon research conducted in the USA 30 years ago.     

Risk Perception in the U.K. Oil and Gas Production Industry: Are Expert Loss‐Prevention Managers' Perceptions Different From Those of Members of the Public?

This article investigates potential differences in risk perception between experts (loss-prevention managers in the U.K. oil and gas production industry) and nonexperts (managers and students). Extant research on expert versus nonexpert perceptions of risk is reviewed, followed by the present study concerning risk perceptions of seven pen-picture scenarios involving the occurrence of hazardous events in the U.K. oil and gas production industry. In contrast to many of the earlier studies of expert versus nonexpert perceptions of risk, the present analysis concludes that experts did not judge the overall riskiness of the portrayed hazardous events as less risky than the nonexperts. Nevertheless, the experts believe more strongly than our nonexperts that the risks portrayed in the scenarios pose little threat to future generations, are more precisely known, and are relatively controllable. Use of multiple regression analysis to help uncover the basis of overall riskiness assessments for expert and lay respondents was inconclusive, however. Finally, little evidence was found that nonexperts were any more heterogeneous in their risk perceptions than experts. It may be that the nature of the risks assessed in the present study may account for the general lack of clear expert versus nonexpert differences in overall perceptions of the riskiness of hazardous events in the North Sea. Earlier findings of strong expert versus nonexpert differences in risk perception assessed hazards of major public concern. It is inferred that using such extreme hazards may have resulted in an exaggerated view of differences in expert versus public (nonexpert) perception of risk.     

Perceptions of Partners' Attributions for Depression in Relation to Perceptions of Support and Conflict in Romantic Relationships

People's attributions for their own psychological problems are linked to their interpersonal behaviors and attitudes. However, depressed individuals' inferences about their romantic partners' attributions for their depressive symptoms have yet to be studied in relation to their perceptions of relationship quality. This study examined perceived support from and conflict with partners in relation to perceptions of partners' attributions for depression in 165 individuals experiencing at least mild depressive symptoms. After controlling for relevant demographic characteristics, perceived internal/controllable psychological attributions were related to greater perceived conflict and lower perceived support, and perceived controllable biological attributions were related to greater perceived conflict. Perceived external/uncontrollable psychological and uncontrollable biological attributions were unrelated to perceived support and conflict. Findings suggest that perceived attributions may help explain the link between depression, support, and conflict in romantic relationships.     

Insurance Policies for Monetary Policy in the Euro Area

In this paper, we aim to design a monetary policy for the euro area that is robust to the high degree of model uncertainty at the start of monetary union and allows for learning about model probabilities. To this end, we compare and ultimately combine Bayesian and worst‐case analysis using four reference models estimated with pre–European Monetary Union (EMU) synthetic data. We start by computing the cost of insurance against model uncertainty, that is, the relative performance of worst‐case or minimax policy versus Bayesian policy. While maximum insurance comes at moderate costs, we highlight three shortcomings of this worst‐case insurance policy: (i) prior beliefs that would rationalize it from a Bayesian perspective indicate that such insurance is strongly oriented towards the model with highest baseline losses; (ii) the minimax policy is not as tolerant towards small perturbations of policy parameters as the Bayesian policy; and (iii) the minimax policy offers no avenue for incorporating posterior model probabilities derived from data available since monetary union. Thus, we propose preferences for robust policy design that reflect a mixture of the Bayesian and minimax approaches. We show how the incoming EMU data may then be used to update model probabilities, and investigate the implications for policy. (JEL: E52, E58, E61)     

The distribution of cook's d statistic

Cook (1977) proposed a diagnostic to quantify the impact of deleting an observation on the estimated regression coefficients of a General Linear Univariate Model (GLUM). Simulations of models with Gaussian response and predictors demonstrate that his suggestion of comparing the diagnostic to the median of the F for overall regression captures an erratically varying proportion of the values.

We describe the exact distribution of Cook's statistic for a GLUM with Gaussian predictors and response. We also present computational forms, simple approximations, and asymptotic results. A simulation supports the accuracy of the results. The methods allow accurate evaluation of a single value or the maximum value from a regression analysis. The approximations work well for a single value, but less well for the maximum. In contrast, the cut-point suggested by Cook provides widely varying tail probabilities. As with all diagnostics, the data analyst must use scientific judgment in deciding how to treat highlighted observations.