Which statement about federal and unitary systems is most accurate? the united states and japan have federal systems, while great britain and canada have unitary systems. today there are more countries with federal systems than with unitary systems. in a federal system, power is concentrated in the states; in a unitary system, it is concentrated in the national government. in a federal system, the constitution allocates powers between states and federal government; in a unitary system, powers are lodged in the national government.