Book excerpt: This Handbook discusses the use of public-private partnerships in law enforcement and security. Written by international experts across multiple disciplines, chapters include case studies and cross-sectional industry-wide studies of private security performance in comparison with public police and collaborated experiences of the two sectors. The Handbook uses existing experiences and public economics to suggest how to improve security and social welfare through greater competition and cooperation between public and private security. This volume provides an integrated framework to assist policymakers in both public and private agencies. This Handbook will be an important reference for scholars in public economics, public administration, criminology, and criminal justice, as well as professionals and policymakers in the public and private sectors.