Horizontal subsidiarity is not social capital: theoretical reflections and a proposal of measurement

Abstract This paper conceptualises and measures horizontal subsidiarity as a key factor of social sustainability, showing its irreducibility to social capital and proposing a formative measurement model to assess it and its connection to socio-economic development. The measurement model is instantiated on Italian regional data for different years. The results reveal a distinct variability in the level of horizontal subsidiarity across regions and a significant impact on social well-being indicators. Horizontal subsidiarity thus emerges as the channel through which social capital generates the common good. Finally, the study emphasises the need for more detailed and granular data to better understand, measure, and model horizontal subsidiarity and its relationship to social and economic development.