The "supra-national" model of EU integration has constructed a multi-level governance and decision-making system among member states, realizing the free flow of factors under market integration. The regional coordinated development mechanism of the EU has certain reference and enlightenment significance for the Guangdong-Hong Kong-Macao Greater Bay Area.

I. The "supra-national" governance structure reduces the transaction cost of the traditional "inter-governmental cooperation"

The EU has achieved the highest level of development and the largest regional integration in the world today. Its greatest innovation is to construct an international regulatory system with supra-national functions on the basis of inter-governmental cooperation. The effective operation of this system is based on the limited transfer and sharing of sovereignty by sovereign states. The development of EU integration is a process of continuous expansion and deepening of the transfer of sovereignty among member states. In many important policy fields such as common agriculture, environment, and competition, member states have transferred some national sovereignty to the supra-national institutions of the EU. The "characteristic" of the EU as a coalition of sovereign states endows the EU institutions with quite high supra-national functions in legislation, administration, and judicature, enabling a series of common policies and regulations in the process of EU integration to be formulated and effectively implemented. For example, the European Commission has the monopoly legislative proposal right for policies at the EU level and has the right to supervise and punish the implementation of EU laws and policies by each member state.

Sovereignty is the foundation of a country. One of the important reasons why each member state can hand over part of its sovereignty to the supra-national institutions of the EU under the premise of consensus is that: As a rational subject, a sovereign state will inevitably pursue the maximization of benefits. The political mechanism in which all cooperation matters are dominated by "bargaining" among governments has seriously hindered the efficient collaborative cooperation of an open economy. Therefore, each member state is eager to reduce its own transaction cost through formal institutional arrangements to ensure that partners can fulfill their promises to promote collective actions and thereby increase each other's benefits.

The supra-national institutions of the EU

1. The Council, including the European Council and the Council of the EU. The European Council, that is, the summit meeting, is composed of the heads of state or government of the member states and the president of the European Commission. It is the highest power body of the EU and is responsible for discussing the internal construction of the EU, important external relations and major international issues. The Council of the EU, originally known as the Ministerial Council, is divided into the General Affairs Council attended by foreign ministers and the specialized councils attended by other ministers of each country. It is the decision-making body of the EU and has the vast majority of the legislative power of the EU.

2. The European Commission is the permanent and executive body of the EU, responsible for implementing the EU treaties and the decisions made by the Council of the EU, and handling the daily affairs of the EU.

3. The European Parliament is the legislative, supervisory and consultative body of the EU and legislates through the common decision-making procedure with the Council of the EU.

4. The Court of Justice of the EU is responsible for hearing and adjudicating various disputes arising in the implementation of EU treaties and relevant regulations.

II. The "supra-national" legal system guarantees the compulsory implementation of the common policies of the EU

Under the existing international rules framework, the cooperation among sovereign states presents complex characteristics - it is both an obligation and a right, and whether to engage in international cooperation depends on the autonomous will of the country. Generally speaking, after confirming the intention of cooperation among countries, they often confirm the rights and obligations of each other by formulating treaties to promote the progress of cooperation. However, the conclusion of a treaty is based on the consent of the country. The country can choose to withdraw from the treaty according to its autonomous will at the beginning, during, and after the conclusion of the treaty, just like the United States easily announcing the withdrawal from the 《Paris Agreement》. Therefore, the compulsory binding force of the treaty is suspected in the international community.

However, the treaties of the European Union are slightly special. The EU legal system, including treaties, regulations, directives, decisions, recommendations, etc., redistributes and defines the powers of various government institutions and the relationships between them, balances the political, economic, social, environmental, health and educational interests of all parties in the process of the development and operation of the community, and provides a code of conduct and an institutional framework for interaction for EU institutions, member state government organizations, businesses and other private organizations. Moreover, over the years, the European Court of Justice and the courts of member states have cooperated tacitly and confirmed through precedents the "principle of supremacy of EU law" and the "principle of direct effect", so that EU law has compulsory binding force on EU member states and can be implemented in the member states. According to the principle of supremacy of EU law, the validity of EU law is higher than the constitutions and other domestic laws of member states. In case of a conflict between EU law and the law of a member state, EU law is given priority. According to the principle of direct effect, once EU law takes effect, it becomes the law of the member state and can be enforced through the judicial system of the member state. Therefore, EU law has become the mechanism guarantee for the orderly promotion of the process of European economic integration and political integration.

Types and Functions of EU Laws

Treaties occupy the position of basic law in EU law. After the EU member states sign and ratify a treaty, the treaty will automatically become a part of domestic law. As a fundamental document, the treaty only stipulates the mission, goals and structure of the operation of the EU in a broad and framework manner, and the specific operation procedures also depend on secondary legal documents such as regulations, directives, decisions, recommendations, etc., as well as the domestic laws of EU member states. At the same time, secondary legal documents are often used as the pilot of EU treaty legislation. The EU often puts forward a specific content through a recommendation first, and then stipulates it in advance through regulations and directives. When the legal provisions become mature and perfect, they will be written into the treaty.

Regulations and directives are typical secondary legal documents of the EU and have compulsory legal binding force. According to Article 288 of the Treaty on the European Union, regulations can be directly applied in all member states without the need for member states to formulate special implementation measures or convert them into domestic law, and member states must not refuse to apply or deviate from the provisions of the regulations. Directives are the most common form of legislation in the EU. The purpose of a directive is to create goals, principles and minimum standards that must be achieved in a specific period for all or part of the EU member states. Only the relevant countries and individuals must comply with a single directive.

The decisions, recommendations and opinions of the EU do not have legal binding force, but only have specific effects. Generally speaking, decisions are made by the Council of the European Union or the European Commission and only have binding force for the recipients of the documents; recommendations and opinions are used to show the EU's attitude and view on specific issues and have important guiding significance for EU member states and individuals.

The "European Court" that Guarantees the Smooth Execution of the Legal System

The European Court of Justice (Court of Justice of the European Union, abbreviated as CJEU) mainly functions to ensure the unified application and interpretation of EU law, as well as to conduct judicial review of the actions of EU community institutions and member states. It was established in 1952 in the city of Luxembourg, and its team of judges is composed of those selected and dispatched by various EU member states. It is the supreme court of the European Union, in charge of the legal appellate hearing of general cases in the EU field and the first instance of special cases. The judicial practice of the European Court has played a key role in the process of European integration. First, it has established the validity of EU law in the entire EU territory. Through judicial practice, the European Court has established some fundamental basic principles of EU law and clarified the relationship between EU law and the laws of member states; second, the European Court has restrained the discretion of member states in regulating the market. It has interpreted the EU treaties through a teleological interpretation method to review whether the laws of member states violate the treaty goals of the EU for the purpose of promoting European integration; third, it has laid the foundation for coordinating the laws of various member states in regulating the market. The European Court has established some important legal principles in the process of promoting EU integration, such as the principle of mutual recognition.

III. The "supra-national" social policy has shaped the "EU identity" of ordinary European people

At the beginning of the development of the EU, the importance of building "European identity" was not realized. Although breakthrough progress has been made in economic integration in many fields such as the customs union and the currency union, it has not enhanced the identification of the people of various member states with the "supra-national" organization of the EU. The long-formed utilitarian concept has made the EU focus too much energy on the development of economic integration and has no time to take care of other issues. Therefore, for a long period of time, social policy has only served as an adjunct to economic integration and has not achieved substantial coordinated results, failed to solve the vital interests that ordinary people care about, and failed to cultivate the people's identification and loyalty to the EU. According to the relevant opinion survey of the EU in 2005, on the question of whether joining the EU is a good thing, there is a large difference in the support rate between the European people and the elite. Only 48% of the people think that joining the EU is a good thing, while the support rate of the elite class on this issue is as high as 96%. On the question of whether the member states can benefit after joining the EU, the support rates of the elite and the people are 91% and 45% respectively.

With the advancement of EU integration, there are more and more and more complex problems encountered. Relying solely on economic means can no longer deal with them effectively, and it is necessary to think about the solution path from a more fundamental social level. Therefore, since the 1990s, the importance of EU social policy has gradually been recognized. In 1992, the "Maastricht Treaty" added a "Social Agreement" in the form of an annex, giving social policy the same status as economic policy, which also means the transformation of EU social policy from subsidiarity to independence. Through promoting the effective implementation of social policies such as common employment and social security, the EU promotes the sharing of the achievements and benefits brought by the development of EU integration among European people, and strives to build an "European identity" that can surpass the national identity of sovereign states, strengthening the "supra-national" sense of belonging and identity consciousness of European people, so as to provide a "dynamic role" for the development of integration.