Existing research on the relationship between work and identity under conditions of increasing work flexibility has provided equivocal results on the threats and challenges for personal identity development within less continuous professional careers. New types of employment-related behaviour have been demanded, such as self-control, self-economisation, and self-rationalisation contained in the concept of "entreployee", in order to conform to requirements stemming from less stable, but also more autonomy-oriented, employment relationships. Some evidence for this new type of employee behaviour has been found, with questions arising about positive and negative effects for the individual having to handle employment risk more, while at the same time also being able to more autonomously organize work and life. Similarly, research on psychological contracts - as direct expression of the reciprocal expectations and obligations by employee and employer - in firms with high work flexibility has shown that employees only partially can gain from offers of competence development and delegation of responsibilities for their own personal development in compensation for increased job insecurity. Interestingly, it seems that those employees can gain more who conform to a traditional, i.e. very continuous, model of work biography and identity. This seeming inconsistency motivates the proposed study, in which hypotheses about different fits between more and less fluid identities in more and less traditional work settings will be explored in a longitudinal investigation. Also, individuals with a higher vs. lower level of personal resources in term of socio-economic status and qualification will be included in the sample in order to further test the assumption that work flexibility might mainly bear opportunities for those with high levels of personal resources for coping with instability and employment risk. A sample of about 250 individuals, equally distributed across these three factors (continuity-oriented vs. non-continuity-oriented identity; employment in one organization with medium to high level of flexibility vs. patchwork employment; low socio-economic status/very little formal vocational training vs. medium socio-economic status/formal vocation or professional training) will be studied in three waves by means of a questionnaire comprising questions on personal identity (biographical continuity, ecological consistency, control orientation, self-esteem), work biography, competence development, and psychological contract. The questions on personal identity will be used to assign the individuals to the two identity types "continuity-oriented" vs. "non-continuity-oriented", which are based on previous own research. Additionally, background information on the organizations, in which the individuals are employed, will be collected in order to determine the degree of flexibility, elements of the psychological contract from the employer's perspective, and measures for competence development undertaken in the companies. The longitudinal approach will permit to form and test predictions about coping patterns by different groups in the sample in view of demands arising from work flexibility, leading to a better understanding of personal, organizational and societal prerequisites for a sound personal identity development.