Causal Relationships between Personal Networks and Health: A Comparison of Three Modeling Strategies

The social contagion of prosocial behaviour: How neighbourhood blood donations influence individual donation behaviour

Life-saving transfusions and numerous other medical treatments are enabled by a minority of people that donate blood. But why do some people repeatedly engage in such prosocial behaviour, especially when it is costly to themselves? This study examines to what extent social contagion within neighbourhoods - changing behaviour in response to the behaviour of others - affects repeated blood donation behaviour. We draw on longitudinal survey and register data from a representative sample of blood donors in the Netherlands from 2007 to 2014 (N = 15,090). Using a panel data model and an instrumental variable approach, we find that donors are positively affected by donations made by other donors living in their neighbourhood. This effect does not seem to be mediated by normative or informational social influence. Exploratory analysis further attributes this finding to social contagion within donor couples. Our study contributes to the literature on repeated blood donation behaviour, and can inform retention strategies of blood banks.

Neighborhood Conditions and Social Network Turnover among Older Adults

Increasing research highlights heterogeneity in patterns of social network change, with growing evidence that these patterns are shaped in part by social structure. The role of social and structural neighborhood conditions in the addition and loss of kin and non-kin network members, however, has not been fully considered. In this paper, we argue that the residential neighborhood context can either facilitate or prevent the turnover of core network relationships in later life - a period of the life course characterized by heightened reliance on network ties and vulnerability to neighborhood conditions. Using longitudinal data from the National Social Life, Health, and Aging Project linked with data from the American Community Survey, we find that higher levels of neighborhood concentrated disadvantage are associated with the loss of older adults' kin and non-kin network members over time. Higher levels of perceived neighborhood social interaction, however, are associated with higher rates of adding non-kin network members and lower rates of adding kin network members over time. We suggest that neighborhood conditions, including older adults' perceptions of neighborhood social life, represent an underexplored influence on kin and non-kin social network dynamics, which could have implications for access to social resources later in the life course.