One of the main branches of Economics is Public Economics, the object of which is the economic activity of the State. The concept of the State in this case includes the Government, Ministries, Public Organizations and Enterprises associated with it, Regions and Municipalities, Social Security Organizations, etc.
Specifically, the object of Public Economics is the study of the economic purposes and goals of the state, as well as the means it has and uses to achieve them.

Today, in societies characterized by private ownership of the means of production, competition in the market, and entrepreneurship, the economic activity of the state has developed to a particularly large extent. In European countries, North America, and Japan, state spending and organizations controlled by it represent about 40 to 45% of GDP, taxes range from 25-30%, and loans from 20-25% of national savings.
At the same time, the state has developed entrepreneurial activity in many sectors such as transportation, electricity production, healthcare, oil refining, etc. At the same time, the state intervenes in the economy in many ways, such as wage regulations, price controls, reforms in various institutions, holding a dominant role in the economy.

It should be noted that in each case, the decisions of the public-economic sector have significant economic effects on the private-economic sector, effects that are the subject of research in Public Economics.

This automatically raises questions about why the state incurs expenses, imposes taxes, takes out loans, establishes or abolishes public enterprises, why it intervenes in the economy with the many means at its disposal, and what are its purposes and goals, as well as who decides on them and how they will be implemented.