Cook Partisan Voting Index

The designated Cook Partisan Voting Index ( CPVI ), often simply as a partisan Voting Index ( PVI), is an index value is calculated based on previous election results and the partisan composition of a U.S. constituency or the U.S. state compared to the state as a whole indicates. It was developed in 1997 by Charlie Cook.

Calculation

The index value is calculated from the election results of the last two U.S. presidential elections. The difference between the respective averages of national election results and result in the constituency or state forms the index value. Depending on whether above average, the Democratic Party or the Republican Party were elected, the numerical value of a D or R is prefixed. A PVI of D 15 for example, means that the result of the Democratic presidential candidate in this constituency the national overall result in the past two elections by an average exceeded 15 percentage points.

Example values

The constituency with the überdurchschnittlichsten result for the Democratic Party is the 15th Congressional District of New York with a PVI of D 43. The " republikanischste " constituency is the 13th Congressional District of Texas with a PVI of R 32. Virginia is currently the only U.S. state with a PVI of 0