Public economics (or economics of the public sector) is the study of government policy through the lens of economic efficiency and equity. Public economics builds on the theory of welfare economics and is ultimately used as a tool to improve social welfare Public administration, the implementation of government policies. Today public administration is often regarded as including also some responsibility for determining the policies and programs of governments. Specifically, it is the planning, organizing, directing, coordinating, and controlling of government operations.Public administration is a feature of all nations, whatever their system of government. Within nations public administration is practiced at the central, intermediate, and local levels. Indeed, the relationships between different levels of government within a single nation constitute a growing problem of public administration. In most of the world the establishment of highly trained administrative, executive, or directive classes has made public administration a distinct profession. The body of public administrators is usually called the civil service. In the United States and a few other countries, the elitist class connotation traditionally attached to the civil service has been either consciously abandoned or avoided, with the result that professional recognition has come slowly and only partially.