A note on stratification and gain in precision in estimating diversity from large samples

Several indices of entropy have been suggested in the literature as weighted diversity measures of a population with respect to a classification process. Among them, Shannon's entropy and Havrda -Charvát's non-additive entropies of order a, have been exhaustively used.

When the population is finite but too large to be censused, the diversity with respect to a given classification process must be estimated from a sample.

In this note, on the basis of an asymptotic study of the sample indices in the stratified random sampling, we are going to confirm that when we deal with large samples one can guarantee a gain in precision from stratified random over simple random sampling. This gain becomes considerable when the ‘inaccuracy" (as intended by Kerridge and Rathie and Kannapan) between the frequency vector in each stratum and that in the whole population, varies greatly from stratum to stratum.     

Behavioural determinants of perceived managerial and leadership effectiveness in Argentina

The purpose of this empirical study was to explore the perceptions of Argentinean managers and non-managerial employees about managerial and leadership effectiveness, and the extent to which the findings are generalized to other countries. The central research question addressed was as follows: How do people employed in Argentinean companies behaviourally distinguish effective managers from ineffective managers, and to what extent are the findings culture-specific or context-general? A total of 42 employees from private and public sector organizations in Cordoba, Argentina, were interviewed using critical incident technique. The interviews generated 302 critical incidents of which 155 were examples of positive (effective) managerial behaviour, and 147 of negative (ineffective) managerial behaviour. The findings suggest that Argentineans perceive as effective those managers who are supportive, considerate, motivating, caring, good decision makers, approachable, participative, fair-minded, communicative, actively involved, and who act as role models. This challenges the widely held belief that Argentineans prefer authoritarian managers over democratic ones.     

An alternative test of Kuznets’ hypothesis

This paper uses a novel approach for testing Kuznets’ hypothesis. Following Kuznets’ original insights, we test for an inverted U relationship between employment outside agriculture and income inequality, instead of the traditional focus on GDP per capita and income inequality. Our results, obtained using panel and country by country regressions, do not support Kuznets’ hypothesis.     

The determinants of fertility in rural Peru: Program effects in the early years of the national family planning program

Using data from the 1991 Peru Demographic Health Survey, a linked Situation Analysis, and a unique region-level data set, this paper examines the determinants of fertility in rural Peru before and after the 1985 enactment of its National Policy on Population. The empirical framework combines a model of the timing and spacing of conceptions with a model of the timing of the placement of family planning services in communities in order to control for non-random placement of services. Results show the program helped reduce fertility post 1985. The magnitude of the effects is quantified with simulations. All correspondence to David Guilkey.We thank the editor and two referees for detailed comments on an earlier draft of this paper. Funding support for this project was provided by the MEASURE Evaluation Project under a Cooperative Agreement between the U.S. Agency for International Development and the Carolina Population Center (Number HRN-A-00-97-0018-00). The views expressed herein are those of the authors and not the sponsoring agency. Responsible editor: Junsen Zhang.     

Trade and environment issues in APEC

The central argument of this article is that regional economic integration must be complemented by the creation of regional frameworks for environmental management. Beyond working to expand market access, Asia-Pacific Economic Cooperation Mechanism (APEC) countries must cooperate to create conditions which provide incentives for sustainable resource and ecosystem use. In this way, trade and environmental policies can mutually reinforce each other. In one way or another, it is likely that environmental issues will be on the agenda. The crucial issue is how deep and broad will be the integration of trade and environmental concerns. This article suggests some guiding principles and innovative strategies.     

How European PR practitioners handle digital and social media

The European Communication Monitor (ECM) 2010 showed that digital communication and social media have grown in importance in the media mix of European organizations. Both new media types are positively correlated to the perceived impact of public relations (PR) in the organization. Specifically social networks and online videos are considered the most important social media tools. Also European practitioners expect that the content of communication will become more important as and when the use of social media further increases. The consequence that everyone within the organization is able to spread information is perceived as the most problematic aspect of social media. A potential problem is that only about one third of the European organizations have implemented social media policies with communication consultancies leading the way. Communication consultants consider social media significantly more important than practitioners working in organizations.     

The gini-simpson index of diversity: estimation in the stratified sampling

In previous papers the problem of estimating the Gini-Simpson index of diversity for large populations has been considered by using random samplings with and without replacement, Nevertheless, the populations to which this estimation is usually applied (e.g., anthropoiogicai, ecological, linguistic and sociological populations) often arise naturally stratified.

In this paper we first construct unbiased estimators of the Gini-Simpson index from a sample drawn according to a stratified sampling with proportional allocation and independently in different strata. Then, we determine the standard error of such estimators. The advantages of the stratification in estimating diversity are later confirmed by means of a practical example. We finally suggest complementary studies that could be additionally developed.     

Linking Social Support to Psychological Distress in the Unemployed: The Moderating Role of Core Self-Evaluations

In this study, an integrative analysis involving social support and core self-evaluations (CSE) as concurrent predictors of psychological distress among unemployed adults was conducted. The main aim of this study was to evaluate the relationship between perceptions of social support and CSE with psychological distress among unemployed adults, as well as whether levels of CSE moderated the relations between social support and psychological distress. Results indicated that, along with the expected direct and additional influence, a significant social support × CSE interaction was found in explaining several dimensions of psychological distress beyond the independent effect of socio-demographic variables, social support and CSE independently. Specifically, we found significant interaction for social support × CSE in explaining stress and anxiety symptoms. Our data provide empirical support for theoretical and conceptual work connecting social support, CSE and psychological distress associated with unemployment suggesting that alone, but also in combination, these contextual and personal resources may be particularly relevant for leading to reduced psychological distress during unemployment. Finally, theoretical implications of the joint study of these constructs and their relation with psychological distress in unemployed people are discussed.     

Demographic transitions: analyzing the effects of mortality on fertility

The effect of mortality reductions on fertility is one of the main mechanisms stressed by the recent growth literature in order to explain demographic transitions. We analyze the empirical relevance of this mechanism based on the experience of developed and developing countries since 1960. We distinguish between the effects on gross and net fertility, take into account the dynamic nature of the relationship, and control for alternative explanatory factors and for endogeneity. Our results show that mortality plays a large role in fertility reductions, that the change in fertility behavior comes with a lag of about 10 years and that both net and gross fertility are affected. We find comparatively little support for explanations of the demographic transition based on changes in GDP per capita.