Restructuring and widespread workplace closures have exposed white-collar workers to unprecedented levels of job insecurity and unemployment. This thesis describes two studies which examined effects on health of job insecurity and job loss in a longitudinal study of 10,308 white-collar British civil servants. Study 1 examined the consequences of short and long-term job insecurity generated by the transfer of work to agencies which were periodically under threat of privatisation. Relative to unaffected controls, self-reported morbidity increased significantly among respondents expecting transfer to an agency. Physiological measurements, such as blood pressure and body mass index, deteriorated significantly among respondents working in an agency. Increases in morbidity were greater in men than women. Study 2 examined the effects of job insecurity and job loss for respondents in one complete Civil Service department sold to the private sector. Data from three time points were analysed: 2 years pre-privatisation (anticipation phase); 3 months pre-privatisation (pretermination phase); and Ilh years post-privatisation. During the anticipation phase, compared with controls, respondents from the department undergoing privatisation experienced an overall increase in self-reported morbidity. By the pre-termination phase adverse changes were also seen in physiological measures. Postprivatisation, respondents were stratified by employment status. Overall, respondents in secure employment enjoyed better self-reported health than those in any other group. Unemployed men and insecurely employed women had the poorest self-reported health. Psychological disorder was significantly associated with insecure employment in both sexes and unemployment in men. Some evidence of health selection out of the workforce was found, but adjustment for preexisting morbidity demonstrated adverse effects on health in excess of those attributable to selection. Changes in work characteristics and health-related behaviours explained little of the effect of employment status on health. Further research on the employment statushealth relationship is required.