Book excerpt: A Brookings Institution Press and the National Academy of Public Administration publication America's complex system of multi-layered government faces new challenges as a result of rapidly changing economic, technological, and demographic trends. An aging population, economic globalization, and homeland security concerns are among the powerful factors testing the system's capacity and flexibility. Major policy challenges and responses are now overwhelmingly intergovernmental in nature, and as a result, the fortunes of all levels of government are more intertwined and interdependent than ever before. This volume, cosponsored by the National Academy of Public Administration (NAPA), defines an agenda for improving the performance of America's intergovernmental system. The early chapters present the current state of practice in intergovernmental relations, including discussion of trends toward centralization, devolution, and other power-sharing arrangements. The fiscal underpinnings of the system are analyzed, along with the long-term implications of current trends in financing at all levels. The authors identify the principal tools used to define intergovernmental management–grants, mandates, preemptions—in discussing emerging models and best practices in the design and management of those tools. In tergovernmental Management for the 21st Century applies these crosscutting themes to critical policy areas where intergovernmental management and cooperation are essential, such as homeland security, education, welfare, health care, and the environment. It concludes with an authoritative assessment of the system's capacity to govern, oversee, and improve. Contributors include Jocelyn Johnston (American University), Shelley Metzenbaum (University of Maryland), Richard Nathan (SUNY at Albany), Barry Rabe (University of Michigan), Beryl Radin (American University), Alice Rivlin (Brookings Institution), Ray Sheppach (National Governors Association), Frank Shafroth (George Mason University), Troy Smith (BYU–Hawaii), Carl Stenberg (University of Nor