The worrying decline of social capital (Putnam in Bowling alone: the collapse and revival of American community. Simon and Schuster, New York, 2000) and the disappointing trends of subjective well-being characterising the US (Easterlin in Nations and households in economic growth. Academic Press, New York, 1974; Easterlin and Angelescu in Happiness and growth the world over: time series evidence on the happinessincome paradox, 2009; Easterlin et al. in Proc Natl Acad Sci 107:22463–22468, 2010) raise urgent questions for modern societies: is the erosion of social capital a feature of the more developed and richer countries or is it rather a characteristic aspect of the American society? To test the hypothesis that the erosion of social capital and declining well-being are not a common feature of richer countries, present work focuses on Luxembourg. The main results are: (1) the erosion of social capital is not a legacy of the richest countries in the world; (2) between 1999 and 2008, people in Luxembourg experienced a substantial increase in almost every proxy of social capital; (3) both endowments and trends of social capital and subjective well-being differ significantly within the population. Migrants participate less in social relationships and report lower levels of well-being; (4) the positive relationship between trends of subjective well-being and social capital found in previous literature is confirmed.