The onset of out-of-wedlock births in Switzerland: A spatial diffusion analysis

The aim of the communication is to analyse the onset of extra-marital births in each district of Switzerland between 1970 and 2000. The starting time of the spread of extra-marital birth differed according to regions. It has, for example, first increased in the French speaking area of Switzerland and in urbanized areas. We suspect a spatial diffusion process. Data we use is the level of out-of-wedlock births for each district of Switzerland at four moments, 1970, 1980, 1990 and 2000. We define the time of the onset of out-of-wedlock births for each district following a method suggested by Bocquet-Appel and Jakobi (1998). We then estimated an event history model of this time in which we introduce as a characteristic a social distance between districts which already experiment an increase of extra-marital births and those which did not. This social distance is considered as a proxy of the nearness between districts. Provisory results show a significant effect of this distance on the hazard rate. Lesser is the distance and higher is the probability of the onset. This result confirms our hypothesis of a diffusion process on the Swiss territory.