Traditional firm structures are currently undergoing drastic change. The changes that the traditional firm is currently undergoing will permit active involvement of labor at all levels of the firm's decision-making process, offer workers substantial job security, protect workers' firm specific investment against excessive losses, guarantee workers at least market rates of return on their human capital and will allow labor a major role in shaping the firm's work rules and the production environment. These changes pose an enormous challenge to practitioners and policy-makers alike. The difficulties of appropriately modeling the new codetermined firms are also formidable. The present collection of papers furnishes building blocks for a better analysis of complex firm structures. The present effort is designed to be a workbook , a point of departure on which new research and teaching is to be built, and a work of reference on what has already been accomplished.