Thèse acceptée le 23 octobre 2020 avec la mention « summa cum laude » à l’unanimité du jury :
Prof. Christian Suter, directeur de thèse, Institut de Sociologie (UNINE) 
Dr. Eric Crettaz, co-directeur de thèse, Haute Ecole de Travail Social Genève (HETS).
Dr. Heinz-Herbert Noll, Social Indicators Research Centre, GESIS, DE-Ladenburg
Prof. Filomena Maggino, Dipartimento di Scienze Statistiche, Sapienza Università di Roma

Summary

This thesis focuses on the concept of economic vulnerability and mainly on the analysis of a group, or a specific socio-economic position of the population, people vulnerable to poverty. Indeed, scientific literature has extensively investigated people in poverty or those with the highest concentration of wealth, but those who suffer to maintain decent living conditions, without any help from the welfare state, are often overlooked by research. This thesis analyzes the effects of this socio-economic position on two concepts: firstly, the subjective well-being and secondly, the quality of life in times of crisis.

The first part of this thesis explores the issue of identifying those who are vulnerable to poverty. The emphasis is placed on the various options available to researchers to identify, using a quantitative approach, people vulnerable to poverty and thus, to better target the group that may face difficulties in maintaining decent living conditions. The first article of the thesis compares four indicators which are poverty, precariousness, deprivation and vulnerability in order to show the different possibilities that exist to identify people belonging to this specific group. 

The second part of the thesis combines two approaches that have never been jointly studied, the vulnerability to poverty and the subjective well-being. Indeed, the objective is to assess whether the subjective well-being of our interest group is different or similar to those defined as being in poverty and who are then recognized as such by the society as a whole. 

Finally, in the third and last part of this thesis, our attention shifts towards a set of vulnerable groups defined as such by either the scientific community or public policies, and we assess the impacts of the economic crises of the early 2000s on four quality of life indicators. This third article combines subjective and objective indicators and gives a clear overview on how vulnerable groups in Switzerland fared during the last two consecutive economic downturns. 

The database used for the analyses in this thesis is the Swiss Household Panel (SHP). This longitudinal database started in 2000 and contains rich information, both objective and subjective, about households living in Switzerland. Each of the three articles follows its own methodology. The first article compares four indicators and their methodological construction, in the perspective to use them to identify people vulnerable to poverty. The second paper first uses the vulnerability to poverty method to define the analysis group and then, the subjective well-being is estimated using a linear regression model (OLS). Finally, the third paper uses different models (binary regressions, multilevel models, fixed-effects and random effects) to estimate which vulnerable groups were affected by economic crises, but also whether there is a recurrent effect following these two crises close in time, on four quality of life indicators (two subjective and two objective). 

The results show that there are different possibilities for identifying people who are vulnerable to poverty, but that more complex indicators, such as the precarious prosperity or the material deprivation approaches, seem to estimate a larger part of the population compared to the relative poverty or vulnerability to poverty approaches. Their subjective well-being appears to be higher than that of people experiencing poverty, but the difference is very small. This group therefore has a satisfaction with life close to that of the most deprived in society. Finally, the analysis of the effects of the different economic crises on quality of life indicators for vulnerable groups showed that the first crisis of the 2000s (the Dot.com Bubble) had a greater negative impact on the quality of life of these groups than the Great Recession. People experiencing long periods of unemployment, large families, people with a low level of education and the solo self-employed are the groups most affected, in terms of quality of life, during consecutive economic crises. 

Keywords: vulnerability to poverty, subjective well-being, quality of life, inequalities, economic crises.