Estimating Contextual Effects from Ego Network Data

Abstract

Network concepts are often used to characterize the features of a social context. For example, past work has asked if individuals in more socially cohesive neighborhoods have better mental health outcomes. Despite the ubiquity of use, it is relatively rare for contextual studies to employ the methods of network analysis. This is the case, in part, because network data are difficult to collect, requiring information on all ties between all actors. This paper asks whether it is possible to avoid such heavy data collection while still retaining the best features of a contextual-network study. The basic idea is to apply network sampling to the problem of contextual models, where one uses sampled ego network data to infer the network features of each context, and then uses the inferred network features as second-level predictors in a hierarchical linear model. We test the validity of this idea in the case of network cohesion. Using two complete datasets as a test, we find that ego network data are sufficient to capture the relationship between cohesion and important outcomes, like attachment and deviance. The hope, going forward, is that researchers will find it easier to incorporate holistic network measures into traditional regression models.

Keywords: Adolescents; Cohesion; Ego Networks; Exponential Random Graph Models; Hierarchical Linear Models; Network Sampling.

Figure 1.

Ego Network Data from Three Hypothetical Respondents

Figure 2.

Measuring Cohesion Using Bicomponent Size

Figure 3.

Estimate of Density and Bicomponent Size by True Values for Add Health Networks

Figure 4.

Boxplots of Density Coefficients for Attachment to School Models

Figure 5.

Boxplots of Bicomponent Cofficients for Attachment to School Models

Figure 6.

Boxplots of Density Coefficients for Behavioral Problems Models

Figure 7.

Boxplots of Bicomponent Coefficients for Behavioral Problems Models