A Work Psychological Model that Works: Expanding the Job Demands-Resources Model

The main purpose of the current thesis was to test and expand the recently developed Job Demands-Resources (JD-R) model. The advantage of this model is that it recognizes the uniqueness of each work environment, which has its own specific job demands and job resources. According to the JD-R model, job demands and job resources evoke two relatively independent processes that explain work-related well-being. Based on the first, health impairment process, high job demands exhaust employees' resources and may therefore lead to energy depletion (i.e. burnout). In contrast, according to the motivational process, job resources, due to their motivational potential, induce employees to meet their goals, and in turn, may lead to work engagement. With a series of cross-sectional and diary studies in various occupations (i.e. home care organizations, electric engineering company, flight attendants, and fast-food restaurant employees), and in two different countries (Greece and The Netherlands), the thesis supported these main assumptions of the JD-R model. Additionally, more evidence was provided for the model's understudied buffer hypothesis. In line with predictions, results revealed that the allocation of specific job resources may mitigate the effect of specific job demands on the core dimensions of burnout (i.e. exhaustion and cynicism), particularly when the levels of demands are high. Furthermore, the thesis addressed one of the most important points of criticism on the JD-R model, namely that it neglects the role of the person in explaining well-being. Particularly, the function of three personal resources (i.e. self-efficacy, organizational-based self-esteem, and optimism) in the model's processes was examined. It was predicted that, personal resources, just like job resources, would moderate the relationship between job demands and burnout. However, this hypothesis was not confirmed. Nevertheless, the studies of the thesis did support the mediating role of personal resources in the model's motivational process both at the between-person, and at the within-person level. The findings showed that resourceful work environments activate feelings of efficiency, significance and optimism in employees. Because employees feel confident and capable, they are motivated to fulfill their tasks, and are more engaged in their work. Consequently, this state of work engagement was found to have a positive impact on performance over short periods of time, and to result in better financial outcomes. Also, it was shown that resourceful environments make employees to feel more capable to perform their tasks without investing excessive effort. Thus, it is likely that they will not become overly fatigued. Furthermore, the thesis provided some evidence that job and personal resources are reciprocal over the course of time. This finding supports the idea of so-called 'resources caravans', according to which the existence of resources generates more resources, in a form of a gain spiral. To conclude, the thesis resulted in an expanded version of the JD-R model that takes into account the dynamic interplay between the work environment and the person in explaining work-related well-being and performance. This expanded JD-R model may be a useful instrument for designing organizational interventions that lead to healthy and engaged employees, and thriving organizations.