An unequal burden: Intra-household dimensions of seasonal health in Tanzania

Seasonal variation in nutritional status is a concern in sub-Saharan Africa. Seasonality in the food consumption of young Tanzanian children has a substantial and negative impact on later life outcomes. Seasonal variation in adult nutritional status has implications for labor productivity and prenatal health. Just as mean poverty status or mean health status varies within households, seasonal patterns in health status are likely to vary within households, as well as the mechanisms underlying seasonal variation. We parameterize and compare seasonality in nutritional status across multiple types of household members in rural, farming households in Tanzania, using a novel anthropometric measure of body mass index z-score that is comparable across adults and children. Young children not yet in school and working adults are most vulnerable to seasonal fluctuations in nutritional status. Children in school and older adults are relatively shielded. Seasonal variation in the nutritional status of working adults can be partly explained by variation in dietary quality and agricultural labor hours. Seasonal variation in the nutritional status of young children is not explained by either factor, nor is it mitigated by market access. Our results suggest we do not understand the data generating process behind seasonality in the nutritional status of young children, despite the critical implications of this seasonality for development and later life productivity.     

The Effect of Behavioral Contagion and Tie-Strength on Calorie Intake in Food Courts

Major contributors to the obesity epidemic are societal and result from sedentary lifestyles and consumption of high-calorie diets. Previous studies suggest that food choice behavior is socially transmissible. Hence, knowledge of the impact of social influence on calorie intake is critical to improve the understanding about the outcomes of policies related to healthful diets. There is the need to analyze the influence of social networks on choosing food in a public place. Thus, we interviewed groups of food court patrons in an all-you-can-eat college dining hall. Results show individuals dining in a group with at least one obese group member are consuming more calories from high-calorie foods and fewer calories from low-calorie foods. Food-related interactions in a group influenced food consumption. Hence, dining with obese peers likely increases calorie intake.     

Regression with imputed covariates: A generalized missing-indicator approach

A common problem in applied regression analysis is that covariate values may be missing for some observations but imputed values may be available. This situation generates a trade-off between bias and precision: the complete cases are often disarmingly few, but replacing the missing observations with the imputed values to gain precision may lead to bias. In this paper, we formalize this trade-off by showing that one can augment the regression model with a set of auxiliary variables so as to obtain, under weak assumptions about the imputations, the same unbiased estimator of the parameters of interest as complete-case analysis. Given this augmented model, the bias-precision trade-off may then be tackled by either model reduction procedures or model averaging methods. We illustrate our approach by considering the problem of estimating the relation between income and the body mass index (BMI) using survey data affected by item non-response, where the missing values on the main covariates are filled in by imputations.     

中国转型经济情境下的商业模式创新:主题设计与量表开发

商业模式创新是网络经济时代企业转型升级的重要载体,其主题设计作为企业获得持续性竞争优势的价值源泉近年来备受关注。鉴于主题设计是情境化的产物,本文结合中国转型经济情境,整合商业模式理论与制度理论,提炼出以开拓性和完善性为主题的商业模式创新设计,并在混合研究的基础上,开发出初始测度量表,而后利用两套独立样本数据分别进行探索性因子分析和验证性因子分析。实证分析结果表明,中国转型经济情境下商业模式创新由2个主题维度和16个测项构成,验证了本研究提出的主题设计框架,并开发出了信度、效度良好的测度量表。本研究弥补了商业模式创新"情境化"的不足,较好地回答了创业企业如何通过商业模式创新进行能动性制度变革,为商业模式创新和转型经济情境下的企业战略做出了理论贡献,也为中国转型情境下创业企业通过商业模式创新实现赶超提供了实践启示。     

Diet diversity,malnutrition and health: Evidence from Kenya

We investigate the effects of diet diversity on health outcomes indicated by the body-mass index (BMI) of Kenyan women in their reproductive age (15–49 years). We estimate the demand for diet diversity (which is a proxy for diet quality) and analyse its relationship with BMI by allowing the effect of diet diversity to vary along the conditional BMI distribution. Results show that diet diversity is associated with a beneficial effect on the lower and upper tails of the BMI distribution, that is, dietary diversity improves BMI for underweight individuals while, at the same time, it reduces BMI for overweight/obese individuals. Specifically, doubling the diet diversity is associated with a 14.7% increase in BMI for underweight women and a 7.0% reduction in BMI of obese women. These results support the hypothesis that diet diversity is associated with optimal BMI and, thus, better health, contributing to the policy discourse concerning the double burden of malnutrition in developing countries.     

Measuring the total impact of demographic and behavioural factors on the risk of obesity accounting for the depression status: a structural model approach using new BMI

Building upon previous studies that highlight considerable overlap in the influential factors of both obesity and depression, we employ a structural model to investigate the direct and indirect impacts of behavioural and demographic factors on obesity. We use new body mass index (BMI) to calculate the obesity status and find a significant relationship between an individual’s depression status and his/her obesity status. The results and simulations imply that demographic and behavioural factors can significantly influence the obesity status both directly and indirectly through their impact on depression. Therefore, this study suggests that models which do not account for these various pathways of influence are most likely misrepresenting the impact of these factors on obesity.     

Gender differences,physical activity and body weight

We investigate the effect of physical activity on bodyweight and the gender differences in such effects, following the copula approach to endogenous switching regression. Using data from the 2006 Behavioral Risk Factor Surveillance System (BRFSS), we find differentiated effects of socio-demographic variables on exercise and on Body Mass Indexes (BMIs), and differentiated effects of exercise on BMI, between genders. Regular exercise, on average, decreases BMI by 1.78 for women and 1.01 for men. Food price away from home has negative effects on BMI of both men and women.     

Dietary patterns and body mass indices among adults in Korea: evidence from pseudo panel data

The debate over the association between dietary patterns and obesity has not been settled in the literature. Some studies suggest that there are significant differences in mean body mass index across dietary patterns whereas other studies refute that result. The objective of this study is to test whether dietary patterns have a significant effect on body mass index in Korean adults when controlling for calorie intake and several sociodemographic factors. We present new evidence derived from pseudo panel data created from a series of cross‐sections. Our results from the pseudo panel analysis show that some of the dietary patterns that were identified from the Korean adults’ food intake survey have a significant effect on body mass index. Specifically, males with the “beef and processed food” (P < 0.05), or “pork and alcohol” (P < 0.05) dietary pattern had significantly higher BMIs, whereas females with the “fast food” (P < 0.1) or “ramen and bakery” (P < 0.01) dietary pattern had higher BMI.     

商业模式创新:国外文献综述及分析框架构建

商业模式创新是商业模式研究领域的一个热点问题。从国外学者对商业模式创新研究文献看,这一研究虽然取得了很多重要成果,但大都缺乏后续研究支持。应从商业模式创新动力、商业模式创新途径、商业模式创新实施、商业模式创新阻力等几个方面对商业模式创新研究进行总结,据此提出商业模式创新的初步分析框架。     

An empirical analysis on the determinants of overweight and obesity in China

Overweight and obesity in adult populations is considered to be a growing epidemic worldwide, and appears to be rapidly increasing in China. From 1992 to 2002, the incidence of overweight in adults increased by 39.0%, while that of obesity doubled. To identify the determinants of adult overweight and obesity in China, micro-level data from a questionnaire survey entitled the ‘Preference Parameters Study,’ which was conducted by the Global Centers of Excellence programme at Osaka University, were analysed. In addition to the entire sample, data from urban and rural subsamples were also analysed in order to investigate whether the determinants of overweight and obesity differed. The results suggested that body mass index (BMI) is correlated with subjective well-being, gender, age, labour intensity and drinking and eating habits among urban respondents, and with age, monthly income, number of siblings and eating habits among rural respondents.