Sociology, to me, is the study of choices in social relations. It explores the motivations for taking actions, examines what choices are available (perceived or real) in relations, and studies the consequences of such choices. Therefore, central to sociology is the analysis of both action and structure: choice behaviors in the context of structural opportunities and constraints. Choices are made within such opportunities and constraints, and choices interacting with structural opportunities and constraints can also alter or create structural opportunities and constraints. These processes necessarily shift between the macrostructure and the microstructure. How to capture and demonstrate these dynamics is what occupies sociologists' time and efforts.

This monograph is about a theory that suggests that actors (whether individual or corporate) are motivated by instrumental or expressive needs to engage other actors in order to access these other actors' resources for the purpose of gaining better outcomes. The core proposition is that such accessed resources embedded in social relations, or social capital, bring about better outcomes. Thus, social capital is social and useful. It is ingrained in social relations and facilitated or constrained by them. But within such structural opportunities and constraints, action makes a difference; given the same extent and array of relations for two actors, the outcomes may differ, depending on their choice behaviors. In this formulation, I accept the prevailing effects of structure and relations. Nevertheless, I want to stress the theoretical significance of choices.