In October 2015 I enrolled a PhD programme under a joint supervision: Caroline Gallez and Sandrine Wenglenski at the laboratory Ville Mobilité Transport, in Paris and Juan Antonio Módenes Cabrerizo at the Centre of Demographic Studies, in Barcelona. According to my academic career, I am a mix between a sociologist and a demographer (have a look at my CV!) Research areas Daily mobility, mobility costs, mobility injunction; Residential mobility, residential «choice», residential career; Urban Changes: public policies, urban economics, periurbanization and urban sprawl, gentrification, spatial segregation; Quantitative methodologies (surveys, census and data from GPS) and qualitative methodologies (semi-structured interviews, biography of the residential career). Provisional Ph. D. title and summary A spatial-temporal approach of the spatial exclusion of the poorest within European metropolises: the case of Barcelona and Marseille To reduce the daily commuting distance to go to work, one may go through residential migration. At the same time, urban changes are noticed: Population grows inside urban areas, daily travel conditions improve, cities spread and the commuting distance within this space increases. It seems that urban change dynamics and habitat cycles favour the most well-off socio-economic groups that benefit from a location in central neighbourhoods or in the well connected peripheries of these metropolises. Therefore, can the lengthening of this commuting reveal the poorest socio-economic groups’ residential and occupational vulnerability? To address this issue, we will rely on a comparative study of the inhabitants of the metropolitan regions of Marseille and Barcelona. The analysis of some residents’ spatial relegation will be assessed from a quantitative analysis of demographic conventional data, GPS data and semi-structured interviews.