This article aims to contribute to the understanding of development inequalities among French metropolitan departments. A traditional Shift-Share analysis focusing on employment growth rates, conducted at the department level over the decade preceding the shock induced by the Covid-19 crisis, confirms the importance of local factors in the processes leading to such inequalities. A statistical analysis of this local component, using linear regression, enables the identification of the key factors influencing development and reveals that geographical characteristics outweigh socio-economic variables, thereby also qualifying the significance of spatial spillovers across French departments. The literature acknowledges the existence of disparities between areas within the French territory, explained by local factors. Our aim is to confirm this and to identify the underlying explanatory factors. The data refer to employment figures and are provided by the French National Institute of Statistics and Economic Studies (INSEE). The shift-share analysis of the data over the period confirms the predominance of local factors over the role of employment structure in shaping regional dynamics. The construction of an explanatory model for the local effect draws on variables identified in the existing literature. In addition to the socio-economic characteristics commonly highlighted in previous studies, a combination of climatic, coastal, and transport variables emerges as a key explanatory factor for the spatial trajectories observed over the study period. However, a significant portion of the local effect remains unexplained, highlighting the need for a more in-depth qualitative analysis of territorial governance—an aspect that could not be addressed through a quantitative approach.