Electoral indexes
Basic electoral indexes
Effective Number of Parties [ENP]
- ENPs - ENP acording to seats
- ENPv - ENP acording to votes
Proportionality Index
competitiveness index
aggregation index
ENP
Markku Laakso and Rein Taagepera’s (1979) Effective Number of Parties Index using the formula:
Proportionality Index
The Proportionality Index used for research is based on Loosemore-Hanby Disproportionality Index (Loosemore, Hanby, 1971: 467-469) takes the formula:
Aggregation Index
To calculate the "ownership" of the most powerful electoral committee, use the Aggregation Index of Lawrence C. Mayer (1980), based on the formula:
Aggregation Index
The higher the value of the index, the more concentrated the party system (Banaś 2016: 53). The maximum value of the index (100) means the extreme concentration of the system by one party winning all the seats.
Competition Index
The Competition Index is calculated using the formula
Competition Index
The values of this index may vary within the range <0,1>. The lower the value, the lower the level of competitiveness within the system. The values no lower than 0,8 are generally perceived as a sign of high level of competitiveness (Antoszewski 2017).
Copy of Electoral Indexes
By Maciej Onasz
