In Europe, as well as in other industrialized economies all over the world, employment relations have undergone profound transformations over the last decades. Large numbers of workers have been displaced, involuntarily employed part-time, or hired on temporary employment contracts. The increasing flexibility in the staffing of organizations is experienced, by many employees, as a threat to the continuation of their employment relationships. A growing body of research suggests that such job insecurity can be of fundamental importance from the occupational health perspective as well as the managerial, due to its effects on employees' work attitudes and well-being. This book addresses the nature of job insecurity and investigates its consequences for individuals, the organizations they work for, as well as their labor unions. It also examines whether factors associated with union membership help employees to cope with employment uncertainty. The book is based on a European project involving Belgium, Italy, the Netherlands, and Sweden. Both individuals and organizations alike are harmed by the increased insecurity that prevails in working life today. By identifying and explaining those factors which result in job insecurity, and examining how the experience affects individuals, organizations, and unions, the authors wish to expand the body of knowledge concerning job insecurity. Such knowledge can lead to a greater focus on this phenomenon within working life, and result in greater effort being put into understanding how preventative measures can be implemented in the future.