Book excerpt: Creating a clear, analytical framework, this comprehensive exploration of the relationship between institutional theory and the study of organizations continues to reflect the richness and diversity of institutional thought—viewed both historically and as a contemporary, ongoing field of study. Drawing on the insights of cultural and organizational sociologists, institutional economists, social and cognitive psychologists, political scientists, and management theorists, the book reviews and integrates the most important recent developments in this rapidly evolving field, and strengthens and elaborates the author’s widely accepted "pillars" framework, which supports research and theory construction. By exploring the differences as well as the underlying commonalities of institutional theories, the book presents a cohesive view of the many flavors and colors of institutionalism. Finally, the book evaluates and clarifies developments in both theory and research while identifying future research directions.