(iii) United States
The US system divides government responsibility among the federal, state, and local levels of power. The Constitution limits the federal government to specific powers, with the states reserving all other powers for themselves. The individual states create and structure local government. Local government includes counties and incorporated cities or towns that function independently of a county.
Some responsibilities lie clearly with the federal government, such as international relations and the postal service. But many situations involve more than 1 level of government. For example, the states traditionally have power over education. But the federal government may influence state choices by creating programs that provide provisional funding for education.
Likewise, the allocation of county and city responsibilities, which varies from state-to-state, may sometimes overlap. For example, county police might have responsibility for patrolling only unincorporated areas within the county, but may have to respond to problems jointly with city police when necessary.