Vendor Selection with Bundling*

Product bundling has become increasingly prevalent not only in consumer goods but also in the industrial sector. We study a purchasing problem in which a buyer must obtain necessary numbers of various stock items from a variety of vendors who charge different prices, have limited capacities and different levels of quality, and offer bundled products at discounted prices. We examine relationships among different bundling scenarios and show that the most general scenario is one in which free items are given to the buyer when sufficient quantities are purchased. We develop a mixed integer linear program that finds the purchasing strategy for the buyer that minimizes the total purchase cost. We present computational results which indicate that the problem is very tractable to solve optimally on a personal computer with standard optimization software. Finally, three extensions of the model are discussed.     

Stochastic Forecasting of Labor Supply and Population: An Integrated Model

This paper presents a stochastic model to forecast the German population and labor supply until 2060. Within a cohort-component approach, our population forecast applies principal components analysis to birth, mortality, emigration, and immigration rates, which allows for the reduction of dimensionality and accounts for correlation of the rates. Labor force participation rates are estimated by means of an econometric time series approach. All time series are forecast by stochastic simulation using the bootstrap method. As our model also distinguishes between German and foreign nationals, different developments in fertility, migration, and labor participation could be predicted. The results show that even rising birth rates and high levels of immigration cannot break the basic demographic trend in the long run. An important finding from an endogenous modeling of emigration rates is that high net migration in the long run will be difficult to achieve. Our stochastic perspective suggests therefore a high probability of substantially decreasing the labor supply in Germany.     

Quality of Life in Intentional Communities

The present study was initiated to investigate levels and predictors of wellbeing among inhabitants of intentional communities (ICs). An anonymous, Internet-based questionnaire was distributed to US and Canadian ICs. Responses were obtained from 913 members. Wellbeing was measured by the widely used satisfaction with life scale (SWLS). Hierarchical linear regression analyses were run to test the predictive validity of Social support, Identity fusion, Meaning in life, Community satisfaction and Life change, and Religious activity above and beyond demographic variables and personality traits. Mean scores on the SWLS were estimated to 5.27 and 5.47 (1–7 scale) for men and women, respectively. The full model explained 41.4% of the variance for men and 38.2% for women. Personality explained 13.4 (men) and 14.4% (women) of the variation, while demographic variables only had a minor impact. Overall, presence of Meaning in life and Social support were the most important predictors. The IC inhabitants reported wellbeing on par with the highest scores previously published. The findings support the contention that sustainability, in the form of a communal lifestyle of low ecological footprint, may be promoted without forfeiting wellbeing.     

Corruption and the ‘Paradox of Redistribution’

The existing literature on the determinants of income redistribution has identified a ‘paradox’. Namely, that countries with a high degree of market income inequality redistribute little, which is in disagreement with the median voter theorem. In a first step, this paper outlines several mechanisms that explain why government corruption might be partially responsible for this ‘paradox’. In a second step, different corruption perception indices and an instrumental variable approach are used to provide empirical evidence that indicates a significant negative impact of corruption on redistribution levels for a sample of 148 developing and developed countries. This finding suggests that, next to political and need factors, government corruption explains to some extent the ‘paradox of redistribution’. This is especially true for many developing countries, given that they typically have relatively high degrees of corruption and low levels of redistribution.     

Vocational Experiences and Quality of Life of Migrants: Overview and Future Research

Quality of life is a complicated concept that has attracted broad attention from multiple disciplines. This article introduces a set of studies that employ diverse approaches to explore how work, vocational, and career experiences shape quality of life among migrants, and proposes a future agenda to extend this stream of research. Specifically, operationalizing quality of life in different ways, research showcased in this special issue has demonstrated how international and intranational migrants achieve, maintain, and enhance their well-being in different life domains. Reflecting on the literature and the showcased studies, this article proposes that future research should advance the current inquiry by better categorizing vocational experiences, uniquely operationalizing of quality of life in migration contexts, taking a more culturally sensitive perspective, and broadening methodological approaches.     

Midwifery management of second-degree perineal tears in New Zealand: A cross-sectional survey of practice

Background

Second-degree tears are the most common form of perineal trauma occurring after vaginal birth managed by New Zealand midwives, although little is known about midwives’ perineal practice.

Providers’ perspectives of barriers experienced in maternal health care among Marshallese women

Problem

Pacific Islanders are disproportionately burdened by poorer maternal health outcomes with higher rates of pre-term births, low birth weight babies, infant mortality, and inadequate or no prenatal care.