The Ranney Index is a way to measure a state's competition between the two major political parties in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

, created by

Austin Ranney J. Austin Ranney (September 23, 1920 – July 24, 2006) was an American political scientist and expert on political parties in the United States. Ranney earned his bachelor's degree at Northwestern University, his master's degree at the University ...

, a prominent political scientist and expert on political parties. A Ranney Score ranges from 0–1, with a 0.0 signifying complete Republican control and a 1.0 signifying complete Democratic control.¹ It is calculated as follows

The Ranney Index Averages three indicators of party success during a particular time period: the percentage of the popular vote for the parties' gubernatorial candidates, the percentage of seats held by the parties in the state legislature, and the length of time plus the percentage of the time that the parties held both the governorship and a majority in the state legislatureHershey, Marjorie R. ''Party Politics in America Eleventh Edition'', p27. 2005, New York

References

Scales {{US-poli-stub