Harold D Green

RAND Corporation, Santa Monica, California, United States

Are you Harold D Green?

Claim your profile

Publications (37)86.64 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Adolescents often befriend peers who are similar to themselves on a range of demographic, behavioral, and social characteristics, including substance use. Similarities in lifetime history of marijuana use have even been found to predict adolescent friendships, and we examine whether this finding is explained by youth's selection of friends who are similar on a range of more proximate, observable characteristics that are risk factors for marijuana use. Using two waves of individual and social network data from two high schools that participated in Add Health (N = 1,612; 52.7 % male), we apply longitudinal models for social networks to test whether or not several observable risky attributes (psychological, behavioral, and social) predict adolescent friendship choices, and if these preferences explain friend's similarities on lifetime marijuana use. Findings show that similarities on several risk factors predict friendship choices, however controlling for this, the preference to befriend peers with a similar history of marijuana use largely persists. The results highlight the range of social selection processes that lead to similarities in marijuana use among friends and larger peer groups, and that also give rise to friendship groups whose members share similar risk factors for substance use. Friends with high "collective risk" are likely to be important targets for preventing the onset and social diffusion of substance use in adolescents.
    Journal of youth and adolescence. 11/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: With marijuana use increasing among American adolescents, better understanding of the factors associated with decreasing use and quitting can help inform cessation efforts. This study evaluates a range of neighborhood, family, peer network, and individual factors as predictors of marijuana use, change, and non-use over one year, and cessation over six years.
    Drug and alcohol dependence. 09/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives. We assessed whether 2 types of public housing-scattered among market-rate housing developments or clustered in small public housing projects-were associated with the perceived health and health behaviors of residents' social networks. Methods. Leveraging a natural experiment in Montgomery County, Maryland, in which residents were randomly assigned to different types of public housing, we surveyed 453 heads of household in 2011. We asked residents about their own health as well as the perceived health of their network members, including their neighbors. Results. Residents in scattered-site public housing perceived that their neighbors were more likely to exercise than residents of clustered public housing (24.7% of network members vs 14.0%; P < .001). There were no significant differences in the proportion of network members who were perceived to have major health problems, depressed mood, poor diet, or obesity. Having more network members who smoked was associated with a significantly higher likelihood of smoking. Conclusions. Different types of public housing have a modest impact on the health composition of one's social network, suggesting the importance of housing policy for health. (Am J Public Health. Published online ahead of print July 17, 2014: e1-e8. doi:10.2105/AJPH.2014.301949).
    American journal of public health. 07/2014;
  • Harold D. Green
    American Anthropologist 03/2014; 116(1). · 1.49 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Homeless men are frequently unsheltered and isolated, disconnected from supportive organizations and individuals. However, little research has investigated these men's social networks. We investigate the structure and composition of homeless men's social networks, vis-a-vis short- and long-term homelessness with a sample of men drawn randomly from meal lines on Skid Row in Los Angeles. Men continuously homeless for the past six months display networks composed of riskier members when compared to men intermittently homeless during that time. Men who report chronic, long-term homelessness display greater social network fragmentation when compared to non-chronically homeless men. While intermittent homelessness affects network composition in ways that may be addressable with existing interventions, chronic homelessness fragments networks, which may be more difficult to address with those interventions. These findings have implications for access to social support from network members which, in turn, impacts the resources homeless men require from other sources such as the government or NGOs.
    Network science (Cambridge University Press). 12/2013; 1(3):305-320.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Although several social network studies have demonstrated peer influence effects on adolescent substance use, findings for marijuana use have been equivocal. This study examines whether structural features of friendships moderate friends' influence on adolescent marijuana use over time. Using 1-year longitudinal data from the National Longitudinal Study of Adolescent Health, this article examines whether three structural features of friendships moderate friends' influence on adolescent marijuana use: whether the friendship is reciprocated, the popularity of the nominated friend, and the popularity/status difference between the nominated friend and the adolescent. The sample consists of students in grade 10/11 at wave I, who were in grade 11/12 at wave II, from two large schools with complete grade-based friendship network data (N = 1,612). In one school, friends' influence on marijuana use was more likely to occur within mutual, reciprocated friendships compared with nonreciprocated relationships. In the other school, friends' influence was stronger when the friends were relatively popular within the school setting or much more popular than the adolescents themselves. Friends' influence on youth marijuana use may play out in different ways, depending on the school context. In one school, influence occurred predominantly within reciprocated relationships that are likely characterized by closeness and trust, whereas in the other school adopting friends' drug use behaviors appeared to be a strategy to attain social status. Further research is needed to better understand the conditions under which structural features of friendships moderate friends' influence on adolescent marijuana use.
    Journal of Adolescent Health 09/2013; · 2.97 Impact Factor
  • Source
    Harold D Green, Joan S Tucker, Kayla de la Haye
    Addiction 09/2013; 108(9):1626-7. · 4.58 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Friends are thought to influence adolescent drug use. However, few studies have examined the role of drugs in friendship selection, which is necessary to draw sound conclusions about influence. This study applied statistical models for social networks to test the contribution of selection and influence to associations in marijuana use among friends in two large high schools (N = 1,612; M age = 16.4). There was evidence for friend selection based on similar lifetime and current marijuana use at both schools, but friends were found to influence the initiation and frequency of adolescent marijuana use in just one of these schools. There was minimal evidence that peer effects were moderated by personal, school, or family risk factors.
    Journal of Research on Adolescence 09/2013; 23(3). · 1.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: AIMS: To identify characteristics of social network members with whom homeless youth engage in drinking and drug use. DESIGN: A multi-stage probability sample of homeless youth completed a social network survey. SETTING: Forty-one shelters, drop-in centers and known street hangouts in Los Angeles County. PARTICIPANTS: A total of 419 homeless youth, aged 13-24 years (mean age = 20.09, standard deviation = 2.80). MEASUREMENTS: Respondents described 20 individuals in their networks, including their substance use and demographics, and the characteristics of the relationships they shared, including with whom they drank and used drugs. Dyadic, multi-level regressions identified predictors of shared substance use. FINDINGS: Shared drinking was more likely to occur with recent sex partners [odds ratio (OR) = 2.64, confidence interval (CI): 1.67, 4.18], drug users (OR = 4.57, CI: 3.21, 6.49), sexual risk takers (OR = 1.71, CI: 1.25, 2.33), opinion leaders (OR = 1.69, CI: 1.42, 2.00), support providers (OR = 1.41, CI: 1.03, 1.93) and popular people (those with high degree scores in the network) (OR = 1.07, CI: 1.01, 1.14). Shared drug use was more likely to occur with recent sex partners (OR = 2.44, CI: 1.57, 3.80), drinkers (OR = 4.53, CI: 3.05, 6.74), sexual risk takers (OR = 1.51, CI: 1.06, 2.17), opinion leaders (OR = 1.24, CI: 1.03, 1.50), support providers (OR = 1.83, CI: 1.29, 2.60) and popular people (OR = 1.16, CI: 1.08, 1.24). CONCLUSIONS: Homeless youth in the United States are more likely to drink or use drugs with those who engage in multiple risk behaviors and who occupy influential social roles (popular, opinion leaders, support providers, sex partners). Understanding these social networks may be helpful in designing interventions to combat substance misuse.
    Addiction 04/2013; · 4.58 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The goal of this study is to better understand the longitudinal cross-lagged associations between popularity, assessed through self-rating and peer nominations, and alcohol use among middle school students. The analytical sample comprises 1,835 sixth- to eighth-grade students who were initially recruited from three California middle schools and surveyed in the fall and spring semesters of 2 academic years. Students reported on their background characteristics, past-month alcohol use, and perceived popularity. Additionally, students provided school-based friendship nominations, which were used to calculate peer-nominated popularity. A cross-lagged regression approach within a structural equation modeling framework was used to examine the longitudinal relationship between popularity (self-rated and peer-nominated) and alcohol use. There was a statistically significant (p = .024) association between peer-nominated popularity and the probability of alcohol consumption at the subsequent survey, but not vice versa. Our results suggest that in a scenario where 8% of students are past-month drinkers, each increase of five friendship nominations is associated with a 30% greater risk of being a current drinker at the next wave. We found no evidence of longitudinal associations between past-month alcohol consumption and self-rated popularity. Popularity is a risk factor for drinking during the middle school years, with peer-nominated popularity being more predictive of use than self-perceptions of popularity. To inform alcohol prevention efforts for middle school students, additional research is needed to better understand why adolescents with a larger number of school-based friendship ties are more inclined to drink.
    Journal of Adolescent Health 01/2013; 52(1):108-15. · 2.97 Impact Factor
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Homeless youth lack the traditional support networks of their housed peers, which increases their risk for poor health outcomes. Using a multilevel dyadic analytic approach, this study identified characteristics of social contacts, relationships, and social networks associated with the provision of tangible and emotional support to homeless youth (N = 419, M age = 20.09, SD = 2.80). Support providers were likely to be family members, sex-partners, or non-street based contacts. The provision of support was also associated with contacts' employment and homelessness status, frequency of contact, shared risk behaviors, and the number of network members that were homeless and employed. The results provide insights into how homeless youth could be assisted to develop more supportive social networks.
    Journal of Research on Adolescence 12/2012; 22(4):604-616. · 1.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: INTRODUCTION: Adolescent smoking studies find evidence of active peer influence and selection processes. However, studies have shown that these processes operate differently depending on context. This study uses SIENA to model coevolutionary processes between smoking and changes in friendship ties, comparing two high schools in which data were collected in identical fashion to explore influence and selection mechanisms with respect to current smoking, and smoking levels. METHODS: This is a longitudinal survey with 2 waves of data. In-home surveys were conducted with students from 2 large high schools in the United States: a West Coast school, and a Midwestern school. Participants were consented students in 10th and 11th grades at the first wave of data collection. The primary measures were self-reported smoking behavior and friendship nominations. RESULTS: There is evidence of influence and selection in both schools for adolescents' smoking status (1 = any smoking) and for level of smoking.Conclusions:These models reflect great similarities in influence and selection processes across schools for different smoking behaviors. However, smoking prevalence may impact the exact mechanisms by which influence and selection operate. Researchers should consider smoking interventions with independent modules addressing different selection and influence processes, implemented based on contextual factors such as the prevalence of smoking.
    Nicotine & Tobacco Research 09/2012; · 2.48 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Few after-school programs target alcohol and other drug (AOD) use because it is difficult to encourage a diverse group of youth to voluntarily attend. The current study describes attendance at a voluntary after-school program called CHOICE, which targeted AOD use among middle school students. Over 4,000 students across eight schools completed surveys and 15% participated in CHOICE. Analyses indicated that there were some differences between CHOICE participants and non-participants. For example, African American and multiethnic students were more likely to attend. Past month alcohol users were more likely to initially attend, and marijuana users were more likely to continue attendance. Thus, CHOICE reached students of different racial/ethnic groups and attracted higher risk youth who may not typically obtain prevention services.
    Journal of Research on Adolescence 09/2012; 22(3):571-582. · 1.99 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: This study examines whether residential neighborhood characteristics influence the initiation of marijuana use and binge drinking, and if these neighborhood factors heighten or dampen peer influences on substance use. METHODS: Predictors of marijuana (N=6516) and binge drinking (N=6630) initiation over a 1-year period were identified using data from the National Longitudinal Study of Adolescent Health. Participants were of ages 12-19 years at baseline. The main predictor variables were neighborhood characteristics, using both objective (proportion of households below the poverty line and female-headed, unemployment rate, residential stability) and subjective (perceived cohesion and safety) measures. Binge drinking was defined as 5 or more drinks in a row. RESULTS: Initiation occurred for 12.9% of adolescents in the case of marijuana and 16.4% for binge drinking. Marijuana initiation was more likely among adolescents who lived in neighborhoods with a higher unemployment rate, and binge drinking initiation was more likely among those who perceived greater safety in their neighborhood, after adjusting for other neighborhood characteristics, demographics, friend characteristics, and behavioral and family risk factors. There was no evidence that neighborhood context moderates the associations of peer factors on initiation. CONCLUSIONS: Select neighborhood characteristics appear relevant to the initiation of marijuana use and binge drinking, although the mechanisms appear to be distinct for each substance. If these results are found to be robust, future research should aim to better understand how neighborhood context influences the initiation of adolescent substance use in order to inform prevention efforts.
    Drug and alcohol dependence 08/2012; · 3.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Homeless youth have elevated risk of HIV through sexual behavior. This project investigates the multiple levels of influence on unprotected sex among homeless youth, including social network, individual, and partner level influences. Findings are based on analyses of an exploratory, semi-structured interview (n = 40) and a structured personal network interview (n = 240) with randomly selected homeless youth in Los Angeles. Previous social network studies of risky sex by homeless youth have collected limited social network data from non-random samples and have not distinguished sex partner influences from other network influences. The present analyses have identified significant associations with unprotected sex at multiple levels, including individual, partner, and, to a lesser extent, the social network. Analyses also distinguished between youth who did or did not want to use condoms when they had unprotected sex. Implications for social network based HIV risk interventions with homeless youth are discussed.
    AIDS and Behavior 05/2012; 16(7):2015-32. · 3.49 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Studies often demonstrate homophily in adolescent smoking behavior, but rarely investigate the extent to which this is due to the peer network processes of selection versus influence. Applying the concept of social distance, this study examines these two processes for smoking initiation. We analyzed socio-centric network data from the National Longitudinal Study of Adolescent Health (N=2065; grades=7th-12th). Social distance (degrees of separation), combined with stability and change in friendship networks, was used to derive indicators of peer selection and influence on initiation. Multilevel modeling was used to predict initiation from these indicators, and propensity score modeling was used to determine whether these associations remained after adjusting for pre-existing differences between initiators and consistent non-smokers. We found that both peer influence and selection effects increased the likelihood of initiation even after adjusting with propensity score weights and demographic controls. While the effect size for peer influence depended on the overall proportion of smokers at the school, the selection effect was independent of the school environment. De-selection and indirect influence effects were not significant after controlling for school norm interactions. The association between peer smoking and adolescent smoking initiation appears to be due to both peer selection and direct influence. However, "friends of friends" effects are likely to be confounded with contextual factors. Given that smoking initiation is primarily associated with close personal interactions between the adolescent and his/her friends, prevention efforts should focus on the role of smoking in fostering personal relationships among adolescents.
    Drug and alcohol dependence 03/2012; 124(3):347-54. · 3.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This longitudinal study examines individual differences in the tendency to initiate (N = 4,612) and escalate (N = 2,837) smoking when adolescents gain a best friend who smokes. Potential moderating factors include self-esteem, depression, problem behavior, school and family bonds, and household access to cigarettes. In addition to acquiring a smoking best friend, initiation was predicted by trouble at school, household access, poorer grades and delinquency, whereas escalation was predicted by depressive symptoms. There was little evidence that the examined individual difference factors moderate the association between gaining a smoking best friend and increased adolescent smoking. Results point to the challenges of identifying factors that may lead adolescents to be more or less susceptible to the influence of pro-smoking friends.
    Journal of Research on Adolescence 03/2012; 22(1):113-122. · 1.99 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: There are many mandated school-based programs to prevent adolescent alcohol and drug (AOD) use, but few are voluntary and take place outside of class time. This cluster randomized controlled trial evaluates CHOICE, a voluntary after-school program for younger adolescents, which reduced both individual- and school-level alcohol use in a previous pilot study. We evaluated CHOICE with 9,528 students from 16 middle schools. The sample was 51% female; 54% Hispanic, 17% Asian, 15% white, 9% multiethnic and 3% African American. Fifteen percent of students attended CHOICE. All students completed surveys on alcohol beliefs and use at baseline and 6-7 months later. We conducted intention-to-treat (ITT) school-level analyses and propensity-matched attender analyses. Lifetime alcohol use in the ITT analysis (i.e., school level) achieved statistical significance, with an odds ratio (OR) of 0.70 and a NNT of 14.8. The NNT suggests that in a school where CHOICE was offered, 1 adolescent out of 15 was prevented from initiating alcohol use during this time period. Although not statistically significant (pā€‰=ā€‰.20), results indicate that past month alcohol use was also lower in CHOICE schools (OR = 0.81; NNT = 45). Comparisons of attenders versus matched controls yielded results for lifetime use similar to school-wide effects (OR = 0.74 and NNT = 17.6). Initial results are promising and suggest that a voluntary after-school program that focuses specifically on AOD may be effective in deterring alcohol use among early adolescents; however, further research is needed as program effects were modest.
    Prevention Science 02/2012; 13(4):415-25. · 2.63 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Childhood abuse has been linked to negative sequelae for women later in life including drug and alcohol use and violence as victim or perpetrator and may also affect the development of women's social networks. Childhood abuse is prevalent among at-risk populations of women (such as the homeless) and thus may have a stronger impact on their social networks. We conducted a study to: (a) develop a typology of sheltered homeless women's social networks; (b) determine whether childhood abuse was associated with the social networks of sheltered homeless women; and (c) determine whether those associations remained after accounting for past-year substance abuse and recent intimate partner abuse. A probability sample of 428 homeless women from temporary shelter settings in Los Angeles County completed a personal network survey that provided respondent information as well as information about their network members' demographics and level of interaction with each other. Cluster analyses identified groups of women who shared specific social network characteristics. Multinomial logistic regressions revealed variables associated with group membership. We identified three groups of women with differing social network characteristics: low-risk networks, densely connected risky networks (dense, risky), and sparsely connected risky networks (sparse, risky). Multinomial logistic regressions indicated that membership in the sparse, risky network group, when compared to the low-risk group, was associated with history of childhood physical abuse (but not sexual or emotional abuse). Recent drug abuse was associated with membership in both risky network groups; however, the association of childhood physical abuse with sparse, risky network group membership remained. Although these findings support theories proposing that the experience of childhood abuse can shape women's social networks, they suggest that it may be childhood physical abuse that has the most impact among homeless women. The effects of childhood physical abuse should be more actively investigated in clinical settings, especially those frequented by homeless women, particularly with respect to the formation of social networks in social contexts that may expose these women to greater risks.
    Child abuse & neglect 01/2012; 36(1):21-31. · 2.34 Impact Factor

Publication Stats

194 Citations
86.64 Total Impact Points

Institutions

  • 2009–2014
    • RAND Corporation
      Santa Monica, California, United States
  • 2012
    • Makerere University
      • School of Women and Gender Studies
      Kampala, Kampala District, Uganda
  • 2009–2011
    • University of Southern California
      • School of Social Work
      Los Angeles, CA, United States