International circulations in Europe at the beginning of the XXIst century. From the study of Euro coins spatial distribution to the modelling of a complex system.
Over the last century, the circulation of money has been used by historians as an indicator of the relationships between people across space and time. The introduction of a single currency, the euro, on January 1, 2002 in 12 European countries offers the opportunity to trace the paths of international mobility in that part of the world. This thesis aims to provide an account of the relations - specific and banal - established between European territories from the analyses of the complex shapes formed by the monetary distribution. The approach is based on the design of a conceptual model formalising the internationalisation of flows exchanged between places in a specified time period. The intensity, diversity and scope of monetary circulation are then matched to diverse forms of international mobility through empirical modelling. This hypothetico-deductive approach is based on the study of more than 20,000 money-bags surveyed in France between June 2002 and December 2011. A case study on Luxembourg allows for observing these traces of international mobility at a finer spatial scale. These analyses reveal a series of factors influencing the spread of foreign coins that fall into three categories: spatio-temporal, territorial and social effects. Finally, an individual-based simulation model is built to study the possible interactions between the different factors in a dynamic and multilevel framework. The thesis concludes that the analysis of money circulation is an accurate way to understand, analyse and differentiate the patterns of international mobility in Europe at different scales