Guido Calabresi and A. Douglas Melamed propose a framework for legal analysis that integrates property and tort law, aiming to address various legal relationships. They introduce the concept of "entitlements" protected by property rules, liability rules, or inalienability rules. The framework is applied to the pollution problem and criminal sanctions to demonstrate its utility. The authors discuss the need for a unified perspective in legal analysis, suggesting that integrating property and tort law can provide a more comprehensive understanding of legal relationships. They define "entitlements" as the fundamental decisions made by a legal system to decide which party will prevail in conflicts of interest. The state must enforce these entitlements and determine how they are protected and transferred. The article explores three types of entitlements: those protected by property rules, those protected by liability rules, and inalienable entitlements. Property rules allow the holder to sell the entitlement voluntarily, while liability rules involve an objective standard determined by the state. Inalienable entitlements cannot be sold or transferred. The authors argue that the choice of entitlements is influenced by economic efficiency, distributional preferences, and other justice considerations. Economic efficiency aims to minimize administrative costs and achieve Pareto optimality, where no party can be made better off without making another party worse off. Distributional preferences focus on wealth distribution and the allocation of specific goods. Other justice reasons include considerations that go beyond efficiency and distribution. The article also examines the rules for protecting and regulating entitlements, including property and liability rules, and inalienability. Property rules allow voluntary transfer, liability rules use an objective standard, and inalienability rules prevent any transfer. The authors discuss the limitations of property rules and the need for liability rules to facilitate beneficial transfers and reduce negotiation costs. Overall, the framework provides a structured approach to understanding and resolving legal conflicts, emphasizing the importance of considering economic efficiency, distributional preferences, and justice in the design of legal rules.Guido Calabresi and A. Douglas Melamed propose a framework for legal analysis that integrates property and tort law, aiming to address various legal relationships. They introduce the concept of "entitlements" protected by property rules, liability rules, or inalienability rules. The framework is applied to the pollution problem and criminal sanctions to demonstrate its utility. The authors discuss the need for a unified perspective in legal analysis, suggesting that integrating property and tort law can provide a more comprehensive understanding of legal relationships. They define "entitlements" as the fundamental decisions made by a legal system to decide which party will prevail in conflicts of interest. The state must enforce these entitlements and determine how they are protected and transferred. The article explores three types of entitlements: those protected by property rules, those protected by liability rules, and inalienable entitlements. Property rules allow the holder to sell the entitlement voluntarily, while liability rules involve an objective standard determined by the state. Inalienable entitlements cannot be sold or transferred. The authors argue that the choice of entitlements is influenced by economic efficiency, distributional preferences, and other justice considerations. Economic efficiency aims to minimize administrative costs and achieve Pareto optimality, where no party can be made better off without making another party worse off. Distributional preferences focus on wealth distribution and the allocation of specific goods. Other justice reasons include considerations that go beyond efficiency and distribution. The article also examines the rules for protecting and regulating entitlements, including property and liability rules, and inalienability. Property rules allow voluntary transfer, liability rules use an objective standard, and inalienability rules prevent any transfer. The authors discuss the limitations of property rules and the need for liability rules to facilitate beneficial transfers and reduce negotiation costs. Overall, the framework provides a structured approach to understanding and resolving legal conflicts, emphasizing the importance of considering economic efficiency, distributional preferences, and justice in the design of legal rules.