This thesis examines the apparent contradiction between, from one side, the major change caused by the regionalisation process involving the affirmation of the French regions as a level of economic development and, from the other side, the inertia of the regional borders until 2015. The regional delimitations have been maintained for sixty years, despite the absence in some regions of metropolitan areas, considered by scientific literature as an indispensable element of development because of the location of the decision-making centres. The objective is therefore to deconstruct the decision-making "black box" by identifying the various factors that constrain actors' decisions and that have led to this paradox, which is a handicap for region...