Aliaksandr Amialchuk

Social Network and Weight Misperception Among Adolescents

It is recognized that public health intervention targeted toward changing lifestyle behaviors to reduce overweight status is a considerable challenge. It is important that individuals recognize their overweight status as a health risk in order for an effective change in lifestyle behaviors to occur, and growing evidence suggests that actual weight and perception of weight status often do not match, especially among adolescents. In this article, we explore the extent to which exposure to heavier peers and parents affects misperception of their own weight status by adolescents. Using data from a nationally representative sample of adolescents, we estimated instrumental variable models with school-level fixed effects to account for bidirectionality of peer influence and environmental confounders. Our results indicate that individuals who live in an environment that exposes them to overweight/obese parents and heavier peers tend to misperceive their weight status and think of themselves to be of lower weight than they actually are. Our analysis also revealed differential effects by gender and type of peers.

Exploring effects of online shopping experiences on browser satisfaction and e‐tail performance

Purpose – The purpose of this paper is to empirically identify categories of online shopping experiences and web site functions facilitating these experiences, and to test the effect of those experiences on browser satisfaction, conversion, and online store performance.Design/methodology/approach – Two analytical methods (survey‐based exploratory factor analysis and secondary data‐based regressions) were employed to test the mediating role of browser satisfaction between online shopping experiences and e‐tail performance for 115 top online retailers during 2006‐2008.Findings – In addition to supporting the existence of such parallel in‐store and online experiences as sensory, cognitive, pragmatic, and relational, a new type of online shopping experience (interactive/engagement) was identified. It comprises customer involvement with the online store and with friends and other shoppers via the online store interface. The mediating role of browser satisfaction in increasing sales and traffic to online stores...

The Influence of Body Weight on Social Network Ties Among Adolescents

Evidence of negative stereotypes, prejudice and discrimination towards obese individuals has been widely documented. However, the effect of a larger body size on social network ties or friendship formations is less well understood. In this paper, we explore the extent to which higher body weight results in social marginalization of adolescents. Using data from a nationally representative sample of adolescents, we estimate endogeneity-corrected models including school-level fixed effects that account for bi-directionality and unobserved confounders to ascertain the effect of body weight on social network ties. We find that obese adolescents have fewer friends and are less socially integrated than their non-obese counterparts. We also find that such penalties in friendship networks are present among whites but not African-Americans or Hispanics, with the largest effect among white females. These results are robust to common environmental influences at the school-level and to controls for preferences, risk attitudes, low self-esteem and objective measures of physical attractiveness.

Racial differences in the influence of female adolescents’ body size on dating and sex

This paper investigates the effect of body size on dating and sexual experiences of white (non-Hispanic) and African American (non-Hispanic) female adolescents. Using data from Add-Health, we estimate the effects of obesity and BMI z-score on the probability of having been involved in a romantic relationship, having ever been touched in the genital area in a sexual way, and having ever engaged in sexual intercourse. We find that obese white teenage girls are less likely to have been in a romantic relationship compared to their non-obese counterparts. In addition, obese white girls are less likely to ever have had sex (intercourse) or to ever have been intimate. There are no systematic differences in relationship experiences and sexual behaviors between obese and non-obese black girls. Overall, the estimated relationships are very robust to common environmental influences at the school-level and to the inclusion of proxies for low self-esteem, attitudes toward sex and interviewer assessment of appearance and personality. Instrumental variables estimates and estimates from models with lagged weight status confirm the overall patterns.

Alcohol consumption and social network ties among adolescents: Evidence from Add Health

Although many studies have estimated the influence of peers on risky health behaviors, few have estimated the gains that adolescents receive from such behaviors, particularly in terms of social payoffs for complying with peer behavior. In this paper, we explore the extent to which alcohol consumption increases popularity of adolescents. Using data from a nationally-representative sample of adolescents, we estimate endogeneity-corrected models with school-level fixed effects to identify the effect of alcohol consumption on social network ties. We find that alcohol consumption leads to an increase in popularity, with the largest gains experienced by white males and females. Our results provide new evidence on the motivation behind adolescent drinking and have important implications for substance abuse interventions.

Adolescent weight gain and social networks: is there a contagion effect?

Previous studies on the spread of obesity in social networks have focused on the contemporaneous effect of peer weight outcomes on individuals. This article is the first to investigate the longer term effects, within adolescence and from adolescence into early adulthood, of peers on individual weight outcomes. Using data from the first three waves of the National Longitudinal Study of Adolescent Health (Add Health), and accounting for correlated effects using a number of empirical strategies including school-level fixed effects and accounting for neighbourhood preferences, we show that Body Mass Index (BMI) and overweight status in a persons friendship network influence their BMI and likelihood of being overweight. The evidence suggests that there is some persistence of the effects of past peer weight experiences on individual weight outcomes during adolescence and into early adulthood. The findings are consistent with adolescence being an important formative period of individuals’ preference for ideal physique and own body weight aspirations. We conclude that policy makers should be particularly concerned with interventions during childhood and adolescence, in order to slow the spread of obesity by promoting a healthy body image and positive health behaviours.

The Influence of Physical Activity on Cigarette Smoking among Adolescents: Evidence from Add Health

INTRODUCTION This article explored the relationship between physical activity and smoking behavior among adolescents using rich longitudinal survey data from a nationally representative sample of adolescents. METHODS Several endogeneity-corrected models were estimated to ascertain the effect of exercise on both the probability of being a smoker and the intensity of cigarette smoking. RESULTS The analysis indicated that 1 additional weekly occurrence of exercise led to a 0.3% decline in the probability of being a smoker and led to a 4.1% reduction in the number of cigarettes smoked by a smoker during a month, a result that was robust to stratification by gender and race/ethnicity. Consistent with the national guidelines, frequencies of physical activity of at least 7 times per week appeared to exhibit the biggest benefits in terms of reduction in smoking for both genders and across races/ethnicities. CONCLUSIONS Reduction in health-damaging smoking behavior among adolescents could be an additional benefit of being physically active. This research documented a new pathway by which even moderate increases in physical activity could result in improved health outcomes by reducing smoking.

Uncovering peer effects mechanisms with weight outcomes using spatial econometrics

Abstract Research about how peers influence weight outcomes among adolescents has yielded mixed findings. This paper seeks to not only estimate these peer effects, but also to distinguish between two mechanisms: social multiplier effects and social norm effects. After estimating an augmented spatial autoregressive model using data from the National Longitudinal Study of Adolescent to Adult Health Survey, this study finds significant peer interactions in body mass index, which can be explained by both mechanisms of peer influence; the social norm effect is much larger than the social multiplier effect. The estimated peer effects for overweight and obesity statuses suggest that peer effects are important for overweight status but not for obesity status, and peer influence for overweight status appears to operate solely through social multiplier effect. These findings provide important information for the design of obesity-prevention interventions in schools.

Cross-cultural and gender associations with anxiety about electronic data hacking

We investigated the impact of data hacking on clinical anxiety and worry. 389 American and 216 Korean college students were recruited, surveyed using the Generalized Anxiety Disorder-7 (GAD-7) questionnaire, and adapted GAD-7 specifically assessing data hacking anxiety. Using confirmatory factor analysis with measurement invariance testing, Koreans scored higher on severity of hacking anxiety items, and differently on factor loadings. Controlling for other variables such as age and prior hacking victimization, cultural group status remained a robust predictor for hacking anxiety. Hacking anxiety in both cultural groups was higher in women than men. Results are placed into the context of theory on information privacy concerns and cross-cultural differences on such concerns. Koreans students evidenced greater anxiety about data hacking than Americans.Koreans evidenced greater anxiety about hacking than general anxiety.Women were higher on hacking anxiety than men.

Contraceptive use and pregnancies in adolescents' romantic relationships: role of relationship activities and parental attitudes and communication.

Objective: In a unified framework, the authors estimate whether romantic relationship activities and parental attitudes predict contraception use and consistency, and whether contraception use and consistency predict pregnancy risk among male and females adolescents in the United States. Methods: Data on 3717 participants of the first 2 waves of the National Longitudinal Study of Adolescent Health (Add Health) who were sexually experienced in their recent romantic relationship were analyzed to examine how presex activities in the romantic relationship and parental attitudes and communication are associated with contraception choices and how contraception choices are associated with pregnancies. Results: In multivariate logistic regression analysis, only some relationship activities and parental communication about contraception were significant predictors of contraception, and their influence differed by gender. Going out with the partner increased contraception consistency among males (odds ratio, 2.04). Discussing contraception with the partner before having first sex increased the odds of ever using contraception for both genders (2.61 for females and 1.59 for males) and increased the odds of consistent contraception for females (1.505). Discussing contraception with parent increased the odds of consistent contraception among females (1.383). Merely, using contraception was not a significant predictor of the risk of pregnancy, whereas using contraception consistently significantly reduced the odds of getting partner pregnant for males (0.413) and the odds of pregnancy of females (0.343). Conclusion: Contraception and pregnancy education programs should take into account qualities of romantic relationship and emphasize consistent use of contraception and communication about contraception between partners and with parents.