This is part 3 of a three-part glossary on the social epidemiology of work organisation. The first two parts deal with the social psychology of work and with organisations.^1,2 This concluding part presents concepts related to labour markets. These concepts are drawn from economics, business and sociology. They relate both to traditional interests in these disciplines and to contemporary ideas on post-industrialisation and globalisation,³ particularly the growth of employment in service industries, the development of a 24-h economy, increased participation of the female labour force and the perceived needs of employers in emerging high-tech economies.^4,5 These changes are of particular interest because they are linked to increasing inequality in earnings and changes in social relationships in employment.⁶ These concepts have the potential to elucidate the pathways through which health is affected by conditions of work as an underlying cause.^7,8

CONTINGENT EMPLOYMENT

Contingent employment refers to work with unpredictable hours or of limited duration.^9,10 Work may be unpredictable because jobs are structured to be of short term or temporary, or because the hours vary in unpredictable ways. The US Bureau of Labour Statistics has adopted the first part of this definition, short-term or temporary work contracts, as its definition of contingent employment, and has considered the second part, unpredictably variable hours, as an alternative employment arrangement, a strategy for increasing the flexibility of work assignments.¹¹ Workers are in contingent employment when they are working on limited-duration contracts, working through temporary work agencies or on call. One form of particular interest is the development of firms specialising in the placement of temporary workers. This industry has grown dramatically in recent years and was a substantial proportion of job growth in the US in the 1990s.¹² Some self-employed workers may be considered to …