How the structural composition of sectors shapes socio-technical transitions

Recent studies provide compelling evidence that transition dynamics differ between sectors. This paper develops a theoretical framework for analysing the <em>structural composition</em> of a sector and how it shapes transition dynamics. We elaborate a conceptual approach, which emphasizes socio-technical configurations and their degrees of institutionalization and mutual alignment as the key building blocks for analysing sector-specific opportunities, barriers and leverage points for transitions. The framework is illustrated with examples from two sectors that fundamentally differ in their structural composition and resulting transition patterns: 1) Urban Water Management, in which one socio-technical configuration is dominating the field globally, and 2) Urban Mobility, which is characterized by a polycentric combination of configurations that provide mobility services in spatially diversified ways. Juxtaposing these two cases shows that the relevant transition dynamics and scales of intervention fundamentally differ between sectors' structural compositions, which opens highly constructive avenues for more sector-specific and spatially sensitive theorizing of transition dynamics, and for deriving policy advice.