Gallagher Index by Country 2025
Gallagher Index Value
0
5
10
15
20
25
30
5 Countries with the Highest Gallagher Index
- The Gallagher Index is a measure of the percentage of votes each political party got in an election compared to the percentage of seats each party actually won.
- In a perfectly balanced election, the Gallagher Index would be 0, indicating each party won the exact percentage of seats as they received votes. However, the simple existence of voting districts can create imbalances, as can gerrymandering and other influences. These imbalances are measured by the Gallagher Index.
- A higher Gallagher Index indicates greater disparity between votes received and seats won for all parties collectively.
In a perfect world, every political election would be flawlessly balanced and fair. However, the fact that voting districts and similar factors are key parts of the electoral process means there are sometimes discrepancies between the number of government seats a particular political party wins and the actual number of votes it receives.
Sometimes referred to as the Least Squares Index, the Gallagher Index assesses how balanced an election actually was by determining the statistical difference between voting distribution and the resulting distribution of legislative seats. A lower Gallagher Index score indicates an election that was more proportionate as far as votes cast to seats won.
Examining Gallagher Index scores from country to country can grant valuable insight into how fair world elections actually are worldwide.
Countries with Lower and Higher Gallagher Index Scores
Germany is consistently one of the countries with a lower overall Gallagher Index (around 3.48 on average), likely due to a representation system known for being comparatively proportional. However, the following countries also demonstrate fairly low average Gallagher scores:
Comparing Gallagher Index scores across various countries can be helpful when assessing government stability, as well as assessing the overall effectiveness of current election processes. It can be helpful in determining the potential for government creation, as well.
Factors That Can Impact Gallagher Scores
Naturally, multiple outside influences can affect a country’s Gallagher Indexes, especially over time. Here are some examples to know.
National Party System
The number of different political parties participating in a given election can absolutely influence how a Gallagher Index plays out, especially if there’s a lot of diversity within the candidate pool.
Electoral System Type
The type of electoral system a country employs (e.g., first-past-the-post, proportional representation, or a hybrid system) has a huge effect on the resulting Gallagher score.
District Size
Smaller voting districts tend to demonstrate scores that reveal more disproportion, so district size is another factor to consider when assessing the impact on potential Gallagher Indexes. Shifts in the boundaries of a given district can affect the resulting scores, as well.
