Describe the concept of 'homophily' in network analysis and its implications for causal inference.

Instruction: Explain what homophily is and discuss how it can complicate the estimation of causal effects in studies involving social networks or similar settings.

Context: Homophily refers to the tendency of individuals to associate and bond with similar others. This question evaluates the candidate's understanding of complex dynamics in social networks that may affect causal analysis. Discussing the implications for causal inference checks the candidate's ability to consider how non-random connections in data can bias results and the strategies to mitigate such biases.