Social capital and especially trust are the foundation of most personal relationships and it is considered a key factor of many economic and social outcomes. The purpose of this study is twofold. First, we investigate the links between social capital (trust and voluntary association membership) and life satisfaction. Then, we analyse the impact of the structure of the country wealth on life satisfaction. Our original empirical approach address simultaneously both questions, using a recursive mixed-process model, with bootstrapped standard errors accounting for the sampling design. The role of social capital regarding the well-being of individuals is preponderant, but we underline that the mechanisms at work are not the same for all countries. The process of well-being improvement corresponds to varying models that depend on the country’s initial stocks of capital.