The public sector refers to the areas of a society that are controlled, operated, or managed by the government. The role of the public sector differs from society to society, based on the ruling political and social doctrine of the region. In a socialist society, the role of the public sector may be far larger than the role of the private sector, whereas in a capitalist society, roles may be equal or the private sector may be more expansive. There are a few basic areas in which the public sector usually takes primary control in most societies, including defense, monetary systems, and foreign policy.
Most countries have a document or agreement that stipulates, to some degree, the role of the public sector. Countries that have written constitutions, for instance, usually include guidelines or laws that decree the rights, responsibilities, and limitations of public domain. Countries that give greater powers to the public sector may tend to have less plainly stated guidelines, since the public sector in such regions may not have any legal responsibility to create such laws. With few exceptions, most societies throughout history have allowed extensive and sometimes total public power through structures such as monarchies and dictatorships. The advent of modern democracy, inspired by the ancient Roman method of government, led to a substantial shift in power balances between the public and private sectors throughout the world.
Nevertheless, for a nation to have a cohesive identity, certain unifying duties tend to be left in the hands of the public sector. National defense, or the creation and use of military forces, is frequently a part of the role of the public sector since the stability of a country relies on all disparate regions being equally protected from harm and attack. Since the public sector is usually in charge of creating and directing defense, it also usually retains power over how troops are paid, training mechanisms, and rules of combat. Foreign policy is another area in which it is important to present a unified front through the public sector, in order to prevent conflicting treaties and agreements. Nations also usually grant governments the right to print and manage money though a central bank, in order to create a stable and universal monetary system that can be used by any private citizen anywhere within the jurisdiction of the country.
Some also believe that the role of the public sector should include the protection and preservation of shared resources, such as air, land, and water. By creating structures such as national parks, or implementing pollution limits, the public sector can guarantee the management of resources by a neutral body, rather than allowing the possibility for one private citizen to infringe on other citizens' rights by harming natural, shared resources.
Beyond these basic responsibilities, the role of the public sector becomes extremely murky and controversial. While social conservatives tend to suggest that the public sector should have rights that extend only to make sure that water comes out of the faucets, social liberals believe that government needs to provide for the health, well-being, and safety of citizens through social welfare programs that include education, financial assistance, and health care. Any discussion on the role of the public sector is likely to include a lively variety of opinions, all of which may or may not have valid considerations. About the most concrete statement that can safely be made with regard to the subject is that the role of the public sector evolves with the socio-political climate of each individual nation.