L'Ile-de-France et ses départements : proximité et économie de localisation

Many recent papers propose a simultaneous assessment of the employment growth and productivity. They make it possible to better understand the adaptation of the territories to changing economic constraints and opportunities. According to the framework of the geographical economics, average territories should experiment positive or negative cumulative phenomena. However, some empirical reports reveal intermediate situations. This is indeed the case of the Ile-de-France area, which belongs to the group of territories characterized by a model of growth described as ?recessive?. This paper shows that this conclusion highly depends on the method applied and on the data used. We proceed in three stages. First section recalls the terms and the stakes of the debates which structure the literature devoted to the evaluation of the respective roles of the territory. The second section reconsiders the case of the Ile-de-France in order to discriminate these two effects. Thanks to the application of the Shift ? Share method we conclude that the ?geographical effect? is negative at the regional level only. Referring to a finer territorial scale enables us to go further in the justification of the simultaneous observation of a high performance and negative local effects. We show then that the logic of polarization which originates agglomeration effects differs according to the studied area.