A statutory board is an autonomous agency of the Government that is established by an Act of Parliament and overseen by a government ministry. Unlike ministries and government departments that are subdivisions of ministries, statutory boards are not staffed by civil servants and have greater independence and flexibility in their operations. There are five Community Development Councils (CDCs) appointed by the board of management of the People's Association (PA) for districts in Singapore. Where there are not less than 150,000 residents in a district, the PA's board of management may designate the chairman of a CDC to be the mayor for the district that the CDC is appointed for. As it is the practice for MPs to be appointed as Chairmen of CDCs, these MPs have also been designated as mayors.