This book offers a comprehensive perspective on policy theories, policy formulation and implementation, and alternative paradigm for dealing with complex social and economic systems. It presents insights into policies on major development sectors, including health, education, urbanization, climate change, innovation, advanced manufacturing, and economic growth. It delves into why public policies matter more than resources and are crucial for shaping the future of a country. It attempts a pioneering effort and delineates a complexity theory framework to deal with uncertainty, nonlinearity, emergence, and evolution. It comprises systems thinking, design thinking, complexity thinking, and tools for complexity analysis. Applicable to a policy system, economy, business, and organization, the complexity theory relies on phenomena like emergence, self-organizing property, adaptation, coevolution, and path dependency, in a clear departure from reductionism and Newtonian paradigm. Through academic rigor, it makes a convincing case for better understanding of application of complexity theory. It covers real-world examples and case studies related to evolution of economies of silicon valleys - Bengaluru (India) and San Francisco Bay (USA). These cases underscore the essentiality of complexity theory. In terms of policy formulations, the book contains a policy design framework covering the science of policymaking, innovative approaches, and methodology for policy design. To deal with dynamic systems, it includes a step-by-step guide for the application of system dynamics. It articulates alternative paradigm - adaptive policies and policy design; alternative theory - complexity theory; and new public organizations and institutional development for meeting the challenges of the 21st century. Aiming to reduce fuzziness, the book combines both researcher's in-depth analysis as well as practitioner's perspective, thus serving as a vital read for scholars of public policy, management, and economics. It emphasizes the primacy of policy process to discern deep understanding from the ground and to integrate micro-level realities and macro-level requirements. It argues for change from Weberian bureaucratic model to adaptive approaches and recommends policy system reforms, highlighting that countries should make the right policy choices early to steer ahead. In doing so, the book serves the requirements of policymakers and thought leaders.