Self-selection Process Research Articles

The dilemma of self-monitoring of blood glucose

In a paper published in Diabetologia last year, Martin et al. [1] reported that self-monitoring of blood glucose (SMBG) in the observational retrospective cohort Retrolective Study ‘Self-monitoring of Blood Glucose and Outcome in Patients with Type 2 Diabetes’ (ROSSO) was associated with significantly decreased diabetes-related morbidity and all-cause mortality even after adjusting for age, sex, comorbidities at diagnosis of diabetes (hypertension, CHD and history of stroke), fasting plasma glucose concentrations, triacylglycerol levels and treatment. These findings remained true for patients not taking insulin. In contrast, in the present issue of Diabetologia, Davis et al. [2] report that, in the observational, prospective Fremantle study, SMBG was not associated with improved outcomes of diabetes-related morbidity, cardiac death or all-cause mortality after adjustment for confounders. The confounders adjusted for in the Fremantle study were age, sex, duration of diabetes, prior CHD, prior peripheral arterial disease, neuropathy, retinopathy, microalbuminuria, systolic blood pressure, total serum cholesterol and current smoking. Surprisingly, there was a significant 79% increased risk of cardiovascular mortality in those patients who were not taking insulin but were performing SMBG. How can the disparate results of these two large studies be explained and what lessons can we learn from them? First, there are many factors that might impinge on the outcomes, especially the macrovascular ones, and taking all the appropriate confounders into account may be problematic. Second, there may be a self-selection process for physicians in terms of who is recommended for, and patients who perform, SMBG. Evidence for the former is the finding that those who perform SMBG have higher glycaemia than those who do not [1, 3]. Evidence for the latter was supplied by a large observational retrospective health plan study in which patients who performed SMBG more frequently had lower HbA1c levels [4]. However, a self-administered questionnaire or a computer-assisted telephone interview administered to plan members (83% of whom responded) revealed that self-care practices and healthy lifestyle behaviours were significantly more common in patients who performed SMBG more frequently. By definition, an observational study is not an experimental one, i.e. interventions are chosen rather than randomly assigned. This leads to the possibility of selection bias which, in turn, means that outcomes may not be caused by the intervention under study [5]. Although identifiable differences can be taken into account when the data are analysed, one cannot be certain that these adjustments are adequate because all of the relevant differences may not be Diabetologia (2007) 50:497–499 DOI 10.1007/s00125-006-0582-z

Imports and Exports at the Level of the Firm: Evidence from Belgium

This paper explores a newly-available panel data set merging balance sheet and international trade transaction data for Belgium. Both imports and exports appear to be highly concentrated among few firms and seem to have become more so over time. Focusing on manufacturing, we find that facts previously reported in the literature for exports only actually apply to imports too. We note that the number of trading firms diminishes as the number of export destinations or import origins increases. The same is true if we consider the number of products traded. With regard to productivity differentials, firms that both import and export appear to be the most productive, followed, in descending order, by importers only, exporters only and non-traders. These results point to the presence of fixed costs; not only of exporting, but also of importing and to a process of self-selection in both export and import markets. Also, the productivity advantage of exporters reported in the literature may be overstated because imports were not considered.

Imports and Exports at the Level of the Firm: Evidence from Belgium

This paper explores a newly-available panel data set merging balance sheet and international trade transaction data for Belgium. Both imports and exports appear to be highly concentrated among few firms and seem to have become more so over time. Focusing on manufacturing, we find that facts previously reported in the literature for exports only actually apply to imports too. We note that the number of trading firms diminishes as the number of export destinations or import origins increases. The same is true if we consider the number of products traded. With regard to productivity differentials, firms that both import and export appear to be the most productive, followed, in descending order, by importers only, exporters only and non-traders. These results point to the presence of fixed costs; not only of exporting, but also of importing and to a process of self-selection in both export and import markets. Also, the productivity advantage of exporters reported in the literature may be overstated because imports were not considered.

Design for movement: linking non-work travel and activity level to local urban design dimensions

With the arising sustainability issues related to both the natural and built environments along with health issues as a result of reduced activity, active modes of travel such as walking and bicycling are being investigated to increase their use to combat such issues in Australian cities. This study through an advanced behavioural modelling approach on four typical suburbs of metropolitan Adelaide, Australia confirms that urban design generally have a modest but sometimes statistically significant effect on modal choices. Well-connected streets, and close proximity to jobs and key functions were shown to induce non-motorised travel. Other exogenous environmental factors such as population density, street quality, and the level of public transport had little influences. From a urban design and planning policy perspective, this suggests that greater daily activity and consequent health and environmental benefits might accrue from designing human-scale, walkable communities that appeal to the preference of different social groups vs investment in master-planned communities in the hope of swaying travel behaviour. That is, pedestrian-friendly places suited to the taste preferences of socio-demographic groups might induce more physical activity over the long run through the process of residential self-selection than overt efforts to create fully planned, attractive and quality landscapes all over suburbia.

Academic Citizenship: An Academic Colleagues’ Working Paper

Universities are facing a critical challenge; university citizenship has steadily declined over the last few decades. As a self-governing entity, most of the foundational elements of a university community are within its own control. As a result, the health and future welfare of the institution depends greatly on the quality of its leaders and robustness of its governing structure. These in turn depend on the quality of those undertaking leadership roles and serving on governing bodies and on the degree to which they reflect its values and aspirations. Maximising the probability that these desiderata will be achieved requires a broad-based faculty willingness to serve conscientiously on these bodies and to serve as administrators to be involved in selecting members, and to be involved on the myriad of sub-committees, task forces, departmental committees, and the like. It is not only an abdication of citizenship to leave governance and administration of the institution to a few willing faculty, it is dangerous and puts at risk the welfare of the institution. Even if these few were all able to place the welfare of the institution above their own particular agendas and their self-interest (not something on which to count), the process of self-selection could not be expected to result in a group that would adequately reflect, represent or understand the breadth and depth of the needs, aspirations and complex circumstances of the entire institution. The larger the pool of willing participants, the greater the probability that those selected will reflect best the institutional diversity. This paper draws out the rights and obligations of faculty citizens embedded in the structural arrangements common to universities in the western world. In part A we examine three fundamental components of those arrangements, components that collectively define certain rights and entail certain obligations of citizenship. These obligations flow in part from essential rights, and also in part from what is necessary to sustain the viability and vibrancy of the community. In Part B, we examine some of these essential obligations of citizenship. In Part C, we make recommendations about how to promote effective citizenship; these recommendations are collected after Part C under the heading “Recommendations.”

Screening Mortgage Default Risk: A Unified Theoretical Framework

This study developed a unified framework for theoretically analyzing a set of mortgage attributes that screens borrower types according to their unobservable default risk. In the presence of asymmetric information, a self-selection process is attained, where lower default risk type borrowers choose a mortgage loan with constant over graduated payment, constant over price-level-adjusted payment, adjustable over fixed rate, low over high loan-to-value ratio, and short over long maturity. The study thus examines, among others, various mortgage attributes, which have never previously been considered in the context of mortgage default under asymmetric information. Accordingly, the theoretical predictions produce further grounds for empirical research on mortgage default.

Diagnostic indicators of sleep apnea in older women and men: A prospective study

Objective The purpose of the present prospective study of older adults was to (1) explore the nature and frequency of sleep disorder in a sample of self-identified, sleepy/tired individuals and (2) compare symptom presentation of women and men who were subsequently diagnosed with sleep apnea/hypopnea. Method Participants were 112 community-based older adults self-identified with daytime sleepiness, fatigue, or insomnia. They underwent medical examination and overnight polysomnographic recording. Sleep quality, daytime sleepiness, fatigue, psychological adjustment, and perceived health were evaluated by self-report measures. Results Results indicated (1) a very high rate of sleep disorder identified by the self-selection process, (2) a male-to-female ratio of 1.2 to 1 for diagnosed apnea/hypopnea syndrome, (3) similar severe apnea signs and symptoms reported by both men and women, and (4) virtually no differences in psychological adjustment and few perceived differences in health limitations between men and women. (5) Female participants with sleep apnea/hypopnea could not be distinguished from participants with insomnia only on the basis of reported symptom presentation alone. Conclusion Our findings suggest a strategy for identifying individuals for referral to a sleep laboratory. The findings also underline the diagnostic importance of medically unexplained complaints of daytime fatigue or sleepiness in older adults for the diagnosis and, ultimately, the effective management of sleep apnea and its attendant health risks.

The Case For Arts Education As A Required Component Of An Accounting Students College Education

A recent study has highlighted the importance of student perceptions of the accounting profession and the resultant self-selection process. This self-selection process may result in students self-selecting into the accounting area who are deficient in the essential qualities for success in the modern accounting profession. Warnock (1996) reports that among 1st year accounting students a still pervasive image of the accountant is that it is not particularly important to have either imagination or verbal qualities or communication or critical thinking skills and thus students who are weak in the above qualities often self-select into accounting as a major. The purpose of this paper is to introduce into the accounting literature the results of an emerging body of research that suggests arts education can enhance or help accounting students overcome these deficiencies.

The German study on sleep‐disordered breathing in primary school children: epidemiological approach, representativeness of study sample, and preliminary screening results

In order to study the prevalence of habitual snoring (HS), obstructive sleep apnoea (OSA), other aspects of sleep-disordered breathing (SDB), and their determinants, we enrolled a cross-section of children from the population of third graders attending regular primary schools in Hannover, Germany. The recruitment strategy followed a multistage, probability-clustered design. Selected schools were compared with eligible schools regarding the percentage of children with low socio-economic status (SES). The recruitment process was analysed and response proportions calculated. Study subjects were compared with their school enrolment cohort based on anonymous data provided by school authorities. Habitual snoring and OSA were investigated using parental questionnaires and all children underwent nocturnal home pulse oximetry. There was a good overall representativeness of sampled schools with regard to the percentage of children with low SES. In total, 1760 children were contacted and 1144 (65.0%) agreed to participate. The whole process of self-selection of study subjects was not differential by gender. Compared with their school enrolment cohort, study subjects had slightly higher educated parents. The prevalence of HS was estimated to be 10.1% [95% CI 8.3, 11.9%]; and 3.2% [2.2, 4.2%] and 3.9% [2.8, 4.2%] had an abnormally high OSA or SDB score respectively. Based on pulse oximetry, 2.4% [95% CI 1.5, 3.4%] had 3 D(90)and 3 D(C), 1.0% [0.4, 1.6%] had the DI(90) > 0.6, and 3.3% [2.2, 4.4%] had the DI(4) > 3.9 and the DI(C) > 0.4. This study sample appears to be highly representative with regard to all available data from the population, and therefore suitable to study the prevalence of HS and OSA. Our prevalence estimates are in the range of other studies.

Developing a Procedure to Correct for Range Restriction That Involves Both Institutional Selection and Applicants’ Rejection of Job Offers

A common research problem in validation studies is the estimation of the population correlation between predictor X and performanceY from a non–randomly selected sample. Procedures for getting unbiased estimates of population correlations in a limited set of conditions in which no rejection of job offers is assumed have been developed. However, in applied selection settings, it is very likely that some of the candidates who have received job offers reject them through a selfselection process. If an estimation model based on the assumption that there is no rejection of job offers via self-selection is used, estimates of population parameters may be biased due to model misspecification. In the current study, a procedure is developed that is applicable to a variety of realistic validation settings, including a setting in which both institutional selection and applicant’s rejection of job offers are involved. Data requirements of the procedure are also discussed.

The interplay between help-seeking and alcohol-related outcomes: divergent processes for professional treatment and self-help groups

This study examined the influence of self-selection, as reflected in alcohol-related functioning, on the duration of professional treatment and Alcoholics Anonymous (AA), and the influence of social causation, as reflected in the duration of treatment and AA, on alcohol-related outcomes. A sample of alcoholic individuals was surveyed at baseline and 1, 3, and 8 years later. At each point, participants completed an inventory that assessed participation in treatment and AA since the last assessment and alcohol-related functioning. There were divergent processes of self-selection and social causation with respect to the duration of participation in professional treatment and AA. Individuals with more severe alcohol-related problems obtained longer episodes of professional treatment, but this self-selection process was much less evident for AA. Longer participation in professional treatment in the first year predicted better alcohol-related outcomes; however, the duration of subsequent treatment was not associated with better subsequent outcomes. In contrast, longer participation in AA consistently predicted better subsequent alcohol-related outcomes. These findings are consistent with a need-based model of professional treatment, in which more treatment is selected by and allocated to individuals with more severe problems, and an egalitarian model of self-help, in which need factors play little or no role in continued participation.

Correspondence analysis for the evaluation of women's profile during post-menopause and hormone replacement therapy

This study illustrates the use of correspondence analysis to identify distinct profiles characterizing hormone replacement therapy (HRT) users and non-users, allowing the visualization of concurrent characteristics associated with this self-selection process. We analyzed cross-sectional information provided by 195 women reporting natural menopause, among 2,240 participants in the Pro-Saude Study (Rio de Janeiro, Brazil). Non-users had an unfavorable profile, including greater weight gain during adult life, older age, later menopause, and less schooling. This analytic tool should be used more extensively in public health research, in exploratory analyses of the relations among a large number of variables in key populations.

Towards a Theory of Self-Segregation as a Response to Relative Deprivation: Steady-State Outcomes and Social Welfare

We model group formation as a response to relative deprivation. We employ two measures of relative deprivation. We show that in the case of each of these measures the process of deprivation-induced self-selection into groups reaches a steady state, and that the steady-state distribution differs from the distribution that would have obtained had group affiliation been chosen so as to maximize rank. We study the social welfare implications of the deprivation-induced process of group formation and show that when individuals are left to pursue their betterment the resulting state tends to fall short of the best social outcome. We present several implications of the model including federalism and the demand for secession.

Understanding Socialization of Teachers and Social Workers: Groundwork for Collaboration in the Schools

Collaboration between social workers and teachers is critical in order to maximize students' achievement in school. These professional groups share attributes including their status in professions where women predominate, whose practice occurs in a bureaucratic setting and whose professionals hold a service orientation. Despite these similarities, differences occur in the socialization of the two professions in relation to: the processes of self-selection to the profession; education and training; and in their orientation to and experiences within the organization of the school. This article articulates these differences and similarities and examines their impact on the processes of collaboration between social workers and teachers. In addition, strategies for bridging the differences are presented and illustrated with examples of successful interdisciplinary collaboration in schools.

Caracterização de linhagens puras selecionadas de guandu (Cajanus cajan (L.) Millsp) (1)

O objetivo do presente trabalho foi caracterizar morfologicamente dezessete linhagens de guandu que haviam sido selecionadas por diversos critérios, em ensaios de avaliação agronômica, após o que haviam passado por processos de autofecundação, seleção e multiplicação, para obtenção de linhagens puras. Teve por objetivos também verificar a eficiência dos descritores utilizados e descrever seu ciclo vegetativo. Foi possível fazer essa descrição e concluir que as dezessete linhagens utilizadas possuíam características distintas, pelas quais podem ser facilmente identificadas. Verificou-se que os descritores utilizados revelaram-se suficientes para caracterizar as dezessete linhagens e que podem ser feitas simplificações nos descritores. As sementes das cultivares comerciais utilizadas no presente trabalho possuíam mistura mecânica.

MAKING THE GRADE IN THE PRISON YARD: WHO TAKES ADVANTAGE OF EDUCATIONAL PROGRAMMING WHILE INCARCERATED?

ABSTRACT Although a multitude of research has focused on the relationship between prison education programming and recidivism, limited research has been devoted to developing and understanding the self-selection process inherent in prison education. This article begins to explain why some inmates participate in prison education and others do not. Analyses rely on a series of logistic regression models constructed by using a representative sample of the U.S. state prison population (Survey of Inmates in State Correctional Facilities 1997) to predict inmate participation in educational programming. Participation in education centers on inmate behaviors during incarceration. Demographic factors and inmate associations with secondary organizations that promote educational pursuits (prior to their current incarceration), however, do not substantially distinguish these two categories of inmates. Suggestions are made on how to motivate inmates to participate in educational programming during incarceration.

Risk, Self Selection and Advice: Banks versus Venture Capitalists

Venture capital has produced an impressive track record in recent years. But the industry is very focused on specific industries and special types of companies. The paper analyses this market separation between bank financed and venture capital backed companies. I find that both venture capitalist and entrepreneur prefer to finance risky projects using venture capital while secure ones should use ordinary bank finance. Distortion in this positive self-selection process is caused by an overinvestment mechanism which allows some low quality entrepreneurs to profit from the venture capitalist's advice. This in turn provides incentives for him to use screening.

The Impact of High School Community Service Programs on Students’ Feelings of Civic Obligation

Proponents of community service programs often claim that such programs succeed in educating youth for democratic citizenship where traditional civics instruction falls short. Yet it is not clear that all service programs envision such citizenship as linked to political engagement and participation. It is hypothesized that only service programs that frame service within a wide political context and offer opportunities for public action increase political engagement as measured by feelings of civic obligation. This citizenship framework may likewise be incorporated in traditional social studies classes with similar effects. This hypothesis is confirmed using panel data comparing the effects of different high school service programs and social studies courses. Path analysis, analyzing a subsample of students in a particularly effective service program, shows that political socialization effects remain even when accounting for self-selection processes.

Perceptions of sex-role stereotypes, self-concept, and nursing role ideal in Chinese nursing students.

This study examined the relationship between sex-role stereotypes, self-concept and the requisite personality characteristics of an ideal nurse in a cohort of Hong Kong nursing students. To rate these concepts a measure of eight comprehensive dimensions of personality perception was administered to 177 nursing students, studying on preregistration and postregistration programs at a Hong Kong tertiary institution. Both male and female nursing students perceived an ideal nurse to possess a profile of traits including being high on the dimensions of emotional stability, application, intellect, helpfulness and restraint. No significant difference between the self-ratings of the male and female students was found, indicating that male students had undergone a highly self-selective process when choosing nursing education under the influence of Chinese cultural stereotypical attitudes towards nursing. A typical Chinese nurse was rated as similar to the typical female in Chinese society by both male and female nursing students. A typical Chinese nurse was rated relatively low on the masculine dimensions of openness, extroversion and assertiveness. The self-ratings of male nursing students more closely approximated the ideal nurse than did the self-ratings of female nursing students. The conclusions highlight implications for the recruitment and education of both male and female nursing students in Hong Kong society.

Educational choice, wage determination, and rates of return to education in Taiwan

This paper estimates educational choice, wage determination, and the rate of return to education in Taiwan using Taiwan's Manpower Utilization Survey data of 1996. As education investment is a self-selection process, this paper adopts a two-stage estimation method. First, a polychotomous ordered probit model is used to estimate the education decision. Second, the wage equations of different educational attainments are estimated by incorporating the possible selection bias obtained in the probit model. Finally, rates of return on each education level are calculated from the estimation results.