Negative vote weight (also known as ''inverse success value'') refers to an effect that occurs in certain elections where votes can have the opposite effect of what the voter intended. A vote for a party might result in the loss of seats in parliament, or the party might gain extra seats by not receiving votes. This runs counter to the intuition that an individual voter voting ''for'' an option in a democratic election should only increase the chance of that option winning the election overall, compared to not voting (
participation criterion
The participation criterion is a voting system criterion. Voting systems that fail the participation criterion are said to exhibit the no show paradox and allow a particularly unusual strategy of tactical voting: abstaining from an election can he ...
) or voting against it (
monotonicity criterion
The monotonicity criterion is a voting system criterion used to evaluate both single and multiple winner ranked voting systems. A ranked voting system is monotonic if it is neither possible to prevent the election of a candidate by ranking them h ...
).
Theory
The effect that a vote for a party might result in the loss of a seat is contrary to the requirement that every vote in a democratic election should have the same weight. It also violates the requirement that the vote may not explicitly run counter to the intention of the voter.
The phenomenon of negative vote weight should not be conflated with "negative votes" in
approval voting
Approval voting is an electoral system in which voters can select many candidates instead of selecting only one candidate.
Description
Approval voting ballots show a list of the options of candidates running. Approval voting lets each voter i ...
systems, which allows a voter to indicate dislike for a candidate without boosting another, for example by introducing an "oppose" option which causes one vote to be deducted from the disliked candidate's vote total.
Germany
The phenomenon of negative vote weight occurred in several past federal elections in Germany, including the
election in 2009. The negative vote weight could occur in a state where a party had
overhang seat
Overhang seats are constituency seats won in an election under the traditional mixed member proportional (MMP) system (as it originated in Germany), when a party's share of the nationwide votes would entitle it to fewer seats than the number of ...
s. In such states, in many circumstances a vote for a party will not increase its national seat total (
MMP allocations are calculated at the national level in Germany), but may increase the proportion of the party's national seats to be allocated to the state where it already had overhang seats (overhang seats being allocated at the state level). This effectively decreased the party's total seat count, and a voter would have been better served by not voting for that party.
The
Federal Constitutional Court of Germany
The Federal Constitutional Court (german: link=no, Bundesverfassungsgericht ; abbreviated: ) is the supreme constitutional court for the Federal Republic of Germany, established by the constitution or Basic Law () of Germany. Since its in ...
ruled on 3 July 2008 that this was unconstitutional, as a negative vote weight is incompatible with the constitutional guarantee of equality and directness. Accordingly, the election law was changed in February 2013.
Other representative democracies
Negative vote weight is possible in national elections in the
Czech Republic
The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
and
Romania
Romania ( ; ro, România ) is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern, and Southeast Europe, Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, S ...
. It can also occur in some of the
Austria
Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...
n states' local elections. In both cases, however, the incidence is lower, and the effect is less pronounced than in Germany.
Referendums
Negative vote weight can occur in
popular referendums that have a vote quorum (where the proposed change is considered only if a minimum number of people vote). A vote ''against'' the proposal can cause the quorum to be satisfied and thus result in the acceptance of the proposal. For this reason, some popular referendums aim for an approving quorum where the proposed change is only considered if a minimum number of people vote ''for'' the proposal.
See also
*
Participation criterion
The participation criterion is a voting system criterion. Voting systems that fail the participation criterion are said to exhibit the no show paradox and allow a particularly unusual strategy of tactical voting: abstaining from an election can he ...
*
Monotonicity criterion
The monotonicity criterion is a voting system criterion used to evaluate both single and multiple winner ranked voting systems. A ranked voting system is monotonic if it is neither possible to prevent the election of a candidate by ranking them h ...
References
{{reflist
Voting theory
Elections in Germany