Commentary on Knowledge Creation and Dissemination in Operations and Supply‐Chain Management

The title of this paper might have been Knowledge Creation and Dissemination in the POM Domain . Instead, these accomplished authors (who shall be dubbed with honorable intentions as RSST) define the POM domain as Operations and Supply‐Chain Management. Thereby, they leave no doubt that the POM domain spans the entire supply chain from shovels in the mine and seeds in the ground to recycled waste that is remanufactured and sold as new (as well as refurbished) products. RSST declare that sustainability of the ecosystem cycle must be achieved (even in the face of disaster conditions) by all institutions. RSST believe that practitioners can be taught the necessary attitudes and skills by business and engineering schools. It is noteworthy that the ecosystem cycle they describe is accompanied by marketing and financial decision cycles running parallel from inception of ideas to the “end of life” closure that starts a new cycle for closed‐loop product planning. For these coexisting, interdependent, all‐encompassing systems, the RSST team leaves no doubt about the evolution of teaching and research opportunities for young POM scholars. These authors focus on the fact that everything that is not morphing is likely to become counterproductive in the not too far future. This is a critical point of view which is based on the fact that the status quo is highly vulnerable. Also, very special is the RSST warning that changes are required in the status quo which must be made without damaging the existing fabric. This non‐disruptive way of doing POM business has been remarkably successful for the cohesion of the field over the past 25 years. There is agreement that it is great to shake things up without tearing those things apart. All of this leads to the conclusion that the advice of these authors (RSST) is correct and valuable. Debate and disputation of these points is encouraged and expected by the RSST team.     

Gender differences in substance use and initiation of sexual activity

Even though widespread efforts have focused on educating young adults about HIV and AIDS, many individuals continue to engage in behaviors that place them at risk. These behaviors include frequent experimentation with alcohol and other drugs prior to sex, engaging in sexual activity with different partners, and inconsistent safe sex practices (Butcher et al. 1991). The combination of these risky behaviors causes increased concern about the spread of HIV among those of college age. This study focused on two behaviors by examining the relationship between substance use during adolescence and early initiation of sexual activity in a sample of 950 subjects aged 19–21 in a mid-sized southern city. Results indicate that early use of alcohol and marijuana relates to earlier initiation of sexual activity and subsequent risky sexual behavior among young adults. Also, gender differences were observed for frequent users of marijuana and alcohol with males engaging in riskier sexual practices. Recommendations for interventions are made.     

Long-term effects of childbearing on mortality: evidence from pre-industrial Sweden

This paper presents an analysis of the impact of childbearing history on later-life mortality for ever-married men and women using historical micro-level data of high quality for southern Sweden. The analysis uses a Cox proportional hazards model, estimating the effects on old-age mortality of number of births and timing of first and last births. By studying the effects of previous childbearing on mortality by sex and social status, we also gain important insights into the mechanisms relating childbearing to mortality in old age. The results show that number of children ever born had a statistically significant negative impact on longevity after age 50 for females but not for males. Analysis by social group shows that only landless women experienced higher mortality from having more children, which seems to indicate that the main explanations are to be found in social or economic conditions specific to females, rather than in the strictly biological or physiological effects of childbearing.     

A modification for use in destabilized populations of brass's technique for estimating completeness of death registration

Summary Brass has developed a method of estimating completeness of death registration using only data on deaths and population by age and sex. In this paper, his method is briefly outlined and the assumptions upon which it is based are discussed. In particular, the implications of the failure of the assumption of stability of the population are investigated. It is found that in populations where mortality has been declining, use of the technique leads to underestimation of completeness. A modification of the technique based on knowledge of the duration and rate of mortality change is proposed for use in such populations. Using simulated destabilized populations, the modification is tested and found to yield more accurate estimates of completeness of death registration than the unmodified technique. The usefulness of the modified technique is further illustrated by applying it to data for Costa Rican females in 1963.     

Resolving inconsistencies in trends in old-age disability: Report from a technical working group

In September 2002, a technical working group met to resolve previously published inconsistencies across national surveys in trends in activity limitations among the older population. The 12-person panel prepared estimates from five national data sets and investigated methodological sources of the inconsistencies among the population aged 70 and older from the early 1980s to 2001. Although the evidence was mixed for the 1980s and it is difficult to pinpoint when in the 1990s the decline began, during the mid- and late 1990s, the panel found consistent declines on the order of 1%-2.5% per year for two commonly used measures in the disability literature: difficulty with daily activities and help with daily activities. Mixed evidence was found for a third measure: the use of help or equipment with daily activities. The panel also found agreement across surveys that the proportion of older persons who receive help with bathing has declined at the same time as the proportion who use only equipment (but not personal care) to bathe has increased. In comparing findings across surveys, the panel found that the period, definition of disability, treatment of the institutionalized population, and age standardizing of results were important to consider. The implications of the findings for policy, national survey efforts, and further research are discussed.     

Befragtenverhalten bei Touchscreen-Befragungen

Touchscreen-Surveys are a new form of data collection which were recently presented in this journal (issue 3/2003). In this article the behaviour of respondents is analysed, using the data of 11 so far completed survey projects as well as additional research (using the same questionnaire in face-to-face and/or paper&pencil surveys; observation of respondents, interviews with drop-outs). For analytical purposes the process of touchscreen-interviewing is divided into three stages: attracting interested persons, convincing them to take part in the survey and keeping their motivation to give answers up to the last question. It can be shown, that the projects had different ‘success’ in the three stages and for each phase certain factors can be identified. In order to attract people the location of the terminal as well as an eyecatching design of the start-screen are crucial; following up, it is important to make clear what kind of terminal it is, as most people would rather expect an information or entertainment offer, but no request to take part in a survey. Therefore the information provided on the start-screen should be clear, additional announcements like posters or instructions on the admission ticket can be useful. The third challenge is to keep the motivation of respondents to answer all question. Like web-surveys, touchscreen-interviewing is characterised by a relatively large number of drop-outs, but as it can be shown only a small part of them is caused by extrinsic reasons (like companying persons). Therefore the conception of the survey (interesting topics, clear wording) are of high importance as they should be able to maintain the peoples interest, while a clear design and good usability has to enable and support their co-operation. Although most of the drop outs break off after the first question(s) and despite of the described suggestions the length of the interview could be shown as still being the crucial factor for the completion rate.     

Estimating Increment-Decrement Life Tables with Multiple Covariates from Panel Data: The Case of Active Life Expectancy*

A fundamental limitation of current multistate life table methodology-evident in recent estimates of active life expectancy for the elderly-is the inability to estimate tables from data on small longitudinal panels in the presence of multiple covariates (such as sex, race, and socioeconomic status). This paper presents an approach to such an estimation based on an isomorphism between the structure of the stochastic model underlying a conventional specification of the increment-decrement life table and that of Markov panel regression models for simple state spaces. We argue that Markov panel regression procedures can be used to provide smoothed or graduated group-specific estimates of transition probabilities that are more stable across short age intervals than those computed directly from sample data. We then join these estimates with increment-decrement life table methods to compute group-specific total, active, and dependent life expectancy estimates. To illustrate the methods, we describe an empirical application to the estimation of such life expectancies specific to sex, race, and education (years of school completed) for a longitudinal panel of elderly persons. We find that education extends both total life expectancy and active life expectancy. Education thus may serve as a powerful social protective mechanism delaying the onset of health problems at older ages.