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Social Capital, Social Cohesion and Health Ichiro Kawachi Professor of Social Epidemiology Harvard School of Public Health Sulzberger Colloquium April 6, 2011 Conceptual approaches to defining “social capital” Level of Analysis Individual Group SC as Cohesion SC as Networks Source: Kawachi, “Social Capital and Health”, In: Handbook of Medical Sociology, 6th edition (2010), chapter 2. Conceptual approaches to defining “social capital” Level of Analysis Individual SC as Cohesion • Perceptions of trust • Civic participation Group • Survey responses aggregated to the group level. • Volunteering. SC as Networks Source: Kawachi, “Social Capital and Health”, In: Handbook of Medical Sociology, 6th edition (2010), chapter 2. Conceptual approaches to defining “social capital” Level of Analysis Individual SC as Cohesion • Perceptions of trust Group • Survey responses aggregated to the group level. • Civic participation • Volunteering. SC as Networks • Position Generator • Whole social network analysis • Resource Generator Source: Kawachi, “Social Capital and Health”, In: Handbook of Medical Sociology, 6th edition (2010), chapter 2. State of Empirical Evidence • Most studies cross-sectional. • Majority of studies have focused on individual-level social capital (trust perceptions, associational membership). • Most studies used self-rated health as endpoint. • Demonstration of contextual effects remain elusive. Springer, 2008 Figure 1: Studies of Individual-Level Trust and Fair/Poor Self-Rated Health (Dichotomous) Hyppaa & Maki (men), 2001 Hyppaa & Maki (women), 2001 Subramanian et al., 2002 Pollack & Knesebeck, 2004 Veenstra, 2005a Kim et al., 2006a Kim et al., 2006b Poortinga, 2006a Poortinga, 2006b Poortinga, 2006c Poortinga, 2006d Yip et al., in press .3 .4 .5 .6 .7 .8 .9 1 Odds Ratio and 95% Confidence Interval Systematic Review of Studies, 1996-November 1, 2006 Source: Kim, Subramanian & Kawachi, 2008. Chapter 8 1.5 2 Figure 2A: Studies of Area-Level Trust and Fair/Poor Self-Rated Health (Dichotomous) With Adjustment for Individual-Level Social Capital Subramanian et al., 2002 Poortinga, 2006a Poortinga, 2006c Yip et al., in press .3 .4 .5 .6 .7 .8 .9 1 Odds Ratio and 95% Confidence Interval Source: Kim, Subramanian & Kawachi, 2008. Chapter 8 1.5 2 Figure 3: Studies of Individual-Level Associational Memberships and Fair/Poor Self-Rated Health (Dichotomous) Hyppaa et al. (men), 2001 Hyppaa et al. (women), 2001 Hyppaa et al., 2003 Lindstrom, 2004 Pollack & Kneseback, 2004 Veenstra, 2005a Kim et al., 2006b Poortinga, 2006a Poortinga, 2006b Poortinga, 2006c Poortinga, 2006d Yip et al., in press .3 .4 .5 .6 .7 .8 .9 1 Odds Ratio and 95% Confidence Interval Source: Kim, Subramanian & Kawachi, 2008. Chapter 8 1.5 2 Figure 4A: Studies of Area-Level Associational Memberships and Fair/Poor Self-Rated Health (Dichotomous) With Adjustment for Individual-Level Social Capital Poortinga, 2006a Poortinga, 2006c Yip et al., in press .3 .4 .5 .6 .7 .8.91 1 1.5 2 Odds Ratio and 95% Confidence Interval Problems in Causal Inference Common method variance Omitted variable bias (e.g. early childhood environment resulting in poor attachment and poor health). Reverse causation (e.g. people participate because they are healthy). What can twin studies accomplish? • Control for inherited characteristics (e.g. temperament, personality, ability). • Control for early rearing environment (e.g. poor attachment → poor social relations & poor health in adulthood) The National Survey of Midlife Development in the US (MIDUS) Twin Study,1995-1996 Twin screening for ~50,000 national representative sample 14.8% presence of twin 60% gave permission to access twin 26% Completed interview (N=998 pairs) Exclude unknown zygosity and separated before 14 (N=54 pairs) Final study sample (N=944 pairs) Fixed effects coefficients for self-rated physical health MZ DZ 0.25 0.2 0.15 0.1 0.05 0 -0.05 -0.1 -0.15 Social trust *p<0.05 *p<0.05 Sense of belonging Volunteer activity Community participation Fixed effects coefficients for depressive symptoms MZ DZ 0.15 0.1 Social trust 0.05 Sense of belonging Volunteer activity 0 -0.05 -0.1 -0.15 -0.2 -0.25 -0.3 *p<0.05 *p<0.05 Community participation Does living in a cohesive community influence health? Indicators of community social cohesion Presence of active community organizations - neighborhood watch group. Informal socializing. - do you have block parties? Neighbors constantly helping each other. - will they pick up your kids from the bus stop? Trust between neighbors. - do you leave your door unlocked when you go out? Mechanisms linking social cohesion to health outcomes Collective action & collective efficacy e.g. mobilizing to protest the closure of emergency services; passage of local smoke-free ordnances… Mechanisms linking social cohesion to health outcomes Informal social control the role of community adults (as opposed to the police) in intervening to stop smoking, drinking, drug use by children. Network closure Johnny’s mom Mrs. Casey (Johnny’s neighbor) Johnny Mechanisms linking social cohesion to health outcomes Exchange of favors / diffusion of information. More cohesive communities = more network closure (all your friends know each other). = less likelihood of freeriding (i.e. receiving favors without reciprocating) because of risk to one’s reputation. New Directions for Social Capital Research • Bonding / Bridging • Determinants of community social cohesion • Causal inference Bonding vs. Bridging Social Capital Bonding social capital – social connections between people who are similar to each other in terms of status (race, social class, gender…). Bonding vs. Bridging Social Capital Bonding social capital – social connections between people who are similar to each other in terms of status (race, social class, etc). e.g. the Ku Klux Klan. Bonding vs. Bridging Social Capital Bridging social capital – social connections that bridge different SES and race/ethnic groups. e.g. integrated Hindu/Muslim associations in India. Yale University Press, 2002 “Do bonding and bridging social capital have differential effects on self-rated health? A community based study in Japan.” T. Iwase, E. Suzuki, T. Fujiwara, S. Takao, Doi H, Kawachi I. JECH, December 16 (2010). Community sample of 2,260 Okayama City residents, 20-80 years old. Inquired about participation in a variety of civic associations (PTA, sports clubs, alumni associations, political campaign clubs, citizen’s groups, and community associations). Distinguished bonding vs. bridging social capital (diversity by occupation, age group, gender). Multivariable-adjusted* odds ratios of poor self-rated health. Type of social capital OR (95% CI) Bonding capital None Low Middle High 1.00 0.82 (0.59-1.13) 0.81 (0.49-1.34) 0.68 (0.32-1.44) *adjusted for sex, age, living arrangement, education, smoking, overweight, and other type of social capital. Multivariable-adjusted* odds ratios of poor self-rated health. Type of social capital OR (95% CI) Bonding capital None Low Middle High 1.00 0.82 (0.59-1.13) 0.81 (0.49-1.34) 0.68 (0.32-1.44) Bridging capital None Low Middle High 1.00 0.72 (0.53-0.98) 0.61 (0.41-0.91) 0.33 (0.19-0.58) *adjusted for sex, age, living arrangement, education, smoking, overweight, and other type of social capital. New Directions for Social Capital Research • Bonding / Bridging • Determinants of community social cohesion • Causal inference Methods (slide courtesy of Dr. Tomoya Hanibuchi) • Using GIS and topographical maps • 5 cross sections: t1 (pre-1890) t2 (1890-1920) t3 (1920-1960) t4 (1960-1980) t5 (post-1980) t3 t2 t1 Settlements t4 t5 Individual samples 31 OR (95% CI) by periods (t1 ~ t5) for SC indicators, estimated by logistic regression models 32 Courtesy of Dr. Tomoya Hanibuchi New Directions for Social Capital Research • Bonding / Bridging • Determinants of community social cohesion • Causal inference Nagoya ←Taketoyo town Taketoyo town population 42,000 45 min from Nagoya Taketoyo Town Intervention In 2007, municipal officials launched campaign to promote healthy aging among citizens. Intervention: Opening of community centers for seniors, called “salons”. Managed by volunteers. Some of the town residents were also participants of an ongoing cohort study (Aichi Gerontological Evaluation Study, AGES). Source: Prof. Katsunori Kondo, personal communication Salon Social Programs ←Ping-Pong Bingo→ Source: Prof. Katsunori Kondo, personal communication But Does X really cause Y? β X Participation in salons Y Good health Alternative Hypothesis #1: Reverse causation. (Good health allows you to participate.) Salon participation β β reverse Good Health Alternative Hypothesis #2: Confounding Association may reflect the influence of omitted variables. Salon participation β Congeniality, temperament. Good health Can we find an instrument? Z Participation in salons Good health Congeniality, etc. Can we find an instrument? Distance to nearest salon Participation in salons Good health Congeniality, etc. 3 sites in 2007 & participants □ site Circle shows 500m most participants come from neighborhood ● participants 2007 3 sites 2008 2 sites 2009 2sites By 2012: total 10 sites Source: Prof. Katsunori Kondo, personal communication % of participants per older persons living in the distance bracket Distance from salons as an instrumental variable 25 20 15 10 5 0 N → (414) (860) (607) (477) (264) (206) Distance from salon (281) (209) (630) 2 Stage Least Squares (2SLS) ˆ Other Pr edictors X k ˆ Other Pr edictors Y X k Participation in the salons & Trust P-values are in parentheses. pˆ articipati on i 0.68 0.69 distance (0.000) Ztrust08 i vi (0.000) 0.15 0 .48 Ztrust06 (0.663) i (0.000) i 0 .026 male (0.568) i 0 .0024 age06 (0.598) i 0.39 participat ion i u i (0.061) • Distance to the salons showed significant linkage to participation to the salons. • The estimated participation in the salons had a marginally significant (10%) effect on trust in 2008 independent of age, sex and trust in 2006. Test for regressor endogeneity In Likelihood Ratio test, H0:ρ(the error correlation)=0 was not rejected (p=0.25), ”participation” is not necessarily an endogenous variable. 45 Participation in the salons & SRH P-values are in parentheses. pˆ articipati on i 0.68 0.69 distance (0.000) Zsrh08 i (0.000) vi (0.000) 1.45 0 .50 Zsrh06 (0.000) i i 0.060 male (0.160) i 0 .019 age06 (0.000) i 0.43 participat ion i u i (0.022) • Distance to the salons showed significant linkage to participation in the salons. • The estimated participation in the salons had a significant (5%) effect on SRH in 2008 independent of age, sex and SRH in 2006. Test for regressor endogeneity In Likelihood Ratio test, H0:ρ(the error correlation)=0 was not rejected (p=0.33), ”participation” is not necessarily an endogenous variable. 46 Findings • ↓distance from salon = ↑participation. • ↑participation (instrumented) = ↑trust of others over 2-year follow-up period, adjusting for baseline trust. • ↑participation (instrumented) = ↑self-rated health over 2year follow-up period, adjusting for baseline health. Professor Katsunori Kondo, Nihon Fukushi University