La Diversitat de l'augment poblacional en quatre comarques de l'àrea metropolitana barcelonina

The study area is that occupied by the four counties that can be considered
to be south western with regard to the great central urban nucleous of Barcelona:
Baix Llobregat, Garraf, Alt Penedès and Baix Penedès. It is the analysis
of how, where and at what periods the population has increased from the
beginning of the twentieth century until the year 2005. Three main streams
of immigration increases that have occurred during the hundred years considered
appear as fundamental factors of which we study especially the second and third ones because of their importance and significance. Other less general
factors, but that often present considerable importance in certain places
and periods, are the complex of motives (beaches, leisure, tourism, etc.) typical
of the coastal area and the internal movements of population that involve
the decrease of residents in some municipalities and the creation of new housing
in other sectors, and finally the conversion into permanent of residences
of homes that were in origin second houses. It is difficult in these moments to
predict the final consequences of the current economic crisis on the third
major migration stream, still in force, and the evolution of the number of
inhabitants in the different sectors.