In this dissertation, I examine the specific mediating mechanisms through which High Performance Work Systems influence overall unit performance. In particular, I draw mainly on two theoretical perspectives, the resource-based view of the firm and behavioral perspective, to propose and test the mediated model of strategic human resource management.

The data were collected from 322 managers and 526 employees for a sample of 76 units of Japanese companies in various industries. The data were aggregated to the unit-level of analysis. On one hand, the data provided support for many of the hypotheses advanced in the dissertation.

The results of the hierarchical regression analyses revealed that High Performance Work Systems was positively related to both the level of human capital that the unit possesses and the collective normative contract that the employees working in the unit share. In addition, the level of human capital and collective normative contract were significantly related to most of the HR-related outcomes, which, in turn, were significantly related to overall unit performance. Moreover, as hypothesized, the level of human capital acted as mediators of the relationship between High Performance Work Systems and HR-related outcomes while HR-related outcomes played the role of mediator on the relationships between the level of human capital or collective normative contract and overall unit performance. On the other hand, the mediating hypothesis for collective normative contract as well as interaction hypothesis for the level of human capital* collective normative contract were not supported. The implications of the findings and future research directions are also discussed.