Voting systems differ in type and ability to safeguard electoral integrity. Each country develops its own electoral system, based on its distinctive political history and culture. Every system has advantages and disadvantages.[1]

Concerns about electoral integrity and the type of voting system chosen may arise when a system is used to exclude a portion of the eligible population, or to deny a seat to a candidate who has won a large share of the vote. Integrity issues may also arise in a system that remains static when changing social or political conditions make reform essential to ensure that the population is better represented.   

The Voting System Affects Election Results

There are a number of different voting systems, each with its own formula for translating votes into seats in the legislature. The choice of voting system may have an impact on government stability, the representation of various social interests and the level of accountability of elected representatives. Although government stability is beyond the scope of election integrity, it is an important issue to consider when selecting a voting system. Representation and accountability have a direct impact on electoral integrity. Representation implies that each vote counts and political parties win a number of seats proportionate to the number of votes they receive. Accountability is crucial for ensuring voter confidence in the electoral process.

Equality of Votes, Government Stability and Confidence in the Electoral Process

In plurality-majority (or, “majoritarian”) systems, the candidate who receives the most votes in an electoral district wins a seat in the legislature. This formula benefits bigger parties at the expense of smaller ones lacking a strong regional presence. The principle of one person, one vote is compromised if voters who support the smallest parties are less likely to be represented. Also, a party with a relatively low percentage of the national vote may obtain a large majority of seats.  At the same time, plurality-majority systems have the advantage of fostering stable governments that are less likely to be forced to depend on a coalition of parties.

In proportional representation (PR) systems, the seats are allocated to the parties based on the percentage of votes each won in the election. This approach promotes the quality of representation of the electoral outcome over subsequent government stability. More parties may be able to have their candidates elected, a situation that can encourage a proliferation of parties. Coalition government is more common, and this can have a negative impact on stability of government. On the positive side, in countries that have opted for proportional representation there is greater voter confidence in the electoral process since the election outcome is more uniform, transparent and fair to the participants.[2] PR systems use different mathematical formulas (“algorithms”) to allocate seats, and the choice of formula may have a significant impact on representation. For example, one formula may ensure a balance between urban and rural areas; another may guarantee representation for a minority or a traditionally under-represented sector of society.[3]

Proportional representation systems may impose electoral thresholds, requiring each party to receive a minimum percentage of votes in order to win a seat. The threshold intentionally seeks to increase the chances of electing a stable and effective government by reducing the number of parties needed to form or support a government. However, integrity becomes an issue if the threshold is used to prevent smaller parties from winning seats so as to restrict the representation of certain minority groups.

The voting system adopted is the result of a political evolution more often than a conscious legislative decision. Proportional representation is quite common, and several plurality-majority systems are considering adopting PR or an improved version known as “mixed member proportional” (MMP). Such a system offers the benefits of both better representation and stable government. New Zealand, for instance, has abandoned its majority system in favour of an MMP system.