Clientelism is a form of informal relations between political parties and other agents, based on the exchange of benefits and favors in return for political support and loyalty. It is a legacy from the socialist era that has been shaping Serbian economic and political life for decades. These clientelistic practices could have a harmful impact on organizations if it affects employees’ organizational commitment negatively. Teachers are especially important for the economy of a country since the quality of teaching has an impact on future generations of individuals who will work, live, and contribute to the local communities and the society. The aim of this study is therefore to find out if and how teachers in the public sector perceive clientelism and how this affects their organizational commitment. A case study was made on one prominent school in Serbia, where interviews were held with eight teachers. The findings suggest that clientelism affects teachers’ organizational commitment negatively in some cases, indicating that the impact of clientelism on teachers’ organizational commitment is person specific. Clientelism does not have a direct impact on teachers’ organizational commitment but impacts commitment through proxies, i.e. antecedents to organizational commitment.

La présente thèse porte sur le harcèlement moral au travail (HMT). Elle a pour objectif d’étudier d’une part ses effets sur la justice organisationnelle (JO), le climat de sécurité psychosociale (PSC), la détresse psychologique, l’intention de quitter l’entreprise et l’engagement affectif. D’autre part, elle cherche à étudier le rôle médiateur du soutien social de la hiérarchie et de la théorie de l’autodétermination (TAD) (satisfaction et frustration des besoins psychologiques).Afin de répondre à ces objectifs, trois études ont été réalisées. La première étude évalue d’une part les effets du HMT sur la détresse psychologique et l’intention de quitter l’entreprise et, d’autre part,le rôle médiateur du soutien social de la hiérarchie. La deuxième étude propose de tester le rôle médiateur de la satisfaction des besoins psychologiques entre les inducteurs organisationnels (HMTet JO) et individuels (l’intention de quitter l’entreprise et l’engagement affectif). Une troisième étude examine, les effets du HMT et le PSC sur les inducteurs individuels (l’intention de quitter l’entreprise et l’engagement affectif) dans le secteur de la santé. Cette dernière étude montre également le rôle médiateur de la frustration des besoins psychologiques. Pour conclure, les résultats de la thèse montrent l'impact négatif du HMT et d'autres facteurs tels que l'OJ et PSC chez les salariés. Soulignons que ces résultats révèlent également que les besoins psychologiques(satisfaction et frustration) jouent un rôle déterminant en milieu organisationnel. La discussion générale de la thèse dégage les implications et les conclusions découlant des études. / This thesis deals with workplace bullying (WB). It aims to study on one hand its effects onorganizational justice (OJ), psychosocial safety climate (PSC), psychological distress, intention toleave the company and emotional commitment. On the other hand, it seeks to study the mediatingrole of the social support of the hierarchy and the theory of self-determination (SDT) (psychologicalneed satisfaction and frustration). To meet these objectives, three studies were conducted. The firststudy evaluates, firstly, the effects of WB on psychological distress and the intention to leave thecompany and secondly the mediating role of the social support of the hierarchy. The second studyproposes to test the mediating role of the satisfaction of psychological needs between theorganizational and individual inducers (WB, OJ, the intention to leave the company and theemotional commitment). A third study examines the effects of BWP and PSC on individual inducers(intention to leave the company and emotional engagement) in the health sector. This last study alsobrings out the mediating role of the frustration of psychological needs. In conclusion, the results ofthe thesis attest the negative impact of bullying at work and other factors such as OJ and PSCamong employees. It should be noted that these results also reveal that psychological needs(satisfaction and frustration) play a determinant role in an organizational environment. The generaldiscussion of the thesis therefore releases the implications and conclusions of the studies.