Public services are an important element of a sustainable development strategy, and they enable the realization of the right to education, health and social protection. They also contribute to the right to housing, employment and a healthy environment. Public cultural services preserve national cultures. In this way, major public networks promote regional planning and the right to transport and communication. Indeed, public services contribute to the exercise of individual freedoms and democracy, giving economic and social content to freedoms which, without them, sometimes remain formal. States spend heavily on research, both through their own institutions and by supporting research by private companies. This research would not take place if the state did not undertake it, and public supervision makes it possible to direct research towards fundamental fields neglected by private research. Public services are subject to various criticisms, of unequal value.