Over the last decade, the transformation of firms' competitive environment has led to substantial changes in work organization and employment. Accounting for these changes, some researchers have emphasized the development of cooperative relations both within firms and across firms' boundaries, while others pointed to the growth of contingent work and the resulting segmentation of the workforce. This paper aims to integrate these various perspectives into a unified framework, and use it to explore organizational transformations within a particular industry. I first discuss the trend toward flexible, cooperative relations within and between firms, before stressing the greater variety of employment patterns identified in the labour market and organizational literature. I then propose an analytical framework based on core-periphery principles, that better account for the diversity of organizational forms and more consistently explains current changes in employment and inter-firm relations. This framework is applied to the New York garment industry, where it helps identify key dynamics in employment and inter-firm relations. On the basis of this empirical work, I draw some insights on broader changes in the economy, and identify further research directions to improve our understanding of the new organizational forms, as well as their implications from the institutional regulation of employment.