The tiao-kuai () system, also known as tiáotiáo-kuàikuài () to emphasize the plurality, describes the quasi-federal arrangement of administration in the People's Republic of China. The term "tiáo" refers to the vertical lines of authority over various sector reaching down from the ministries of the central government. "Kuài" refers to the horizontal level of authority of the territorial government at the provincial or local level. According to political scientist Kenneth Lieberthal, "The former coordinates according to function ( example, environment); the latter coordinates according to the needs of the locality that it governs." Thus a local environmental protection bureau may have reporting responsibilities to both the central government's State Environmental Protection Administration and to the mayor of the city in which it is located.