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Elections: electoral systems - Coggle Diagram
Elections: electoral systems
types
majority system
alternative vote
candidates ranked by voters, majority of first preference votes wins. If this fails, lowest candidates' votes are redistributed until someone has majority
two-round system
if no candidate wins majority, 2 runners up face runoff election
proportional representation
variety
level of threshold: number of votes needed to get into parliament, depends per country
district magnitude: the larger the district, the more proportionate the electoral outcome
degree of choice of candidates: open or (semi) open lists, single transferable vote
formula for seat allocation
list system
multi-member districts and list of candidates, seats are divided up in proportion to number of votes
single transferable vote
voters rank candidates, winners are determined by a quota based on a formula and a series of counts
plurality system
single member plurality (SMP)
vote for individual candidates
winning candidate requires more votes than any other single candidate (not necessarily majority)
mixed systems
parallel, or mixed member majoritarian
some seats determined by PR, others by SMP or two-round elections
mixed member proportional
much like MMM except that PR seats are used to adjust the total share of seats
party systems
Duverger law
mechanical effects: it is harder for smaller parties to get into parliament
psychological: voters start voting strategically, reinforcing the mechanical effects
questions about whether it is a law or an empirical tendency
aims
simplicity:
system should be comprehensible to voters
responsiveness:
there should be a link between constituents and representatives of parliament
effectiveness:
strong and stable governments, regardless of proportionality
there are always trade-offs between these principles, depends on which ones are favored
proportionality:
parliaments should mirror society
consequences
plurality and majority systems lead to disproportionality and underrepresentation, but they ensure stable party systems and one-party governments
party systems
majority representation
disproportionality
manipulations
courts often play a huge role
district boundaries (majoritarian system)
malapproportionment:
strategically ignoring changes in the voting populations of particular electoral districts (ignoring effects of depopulation rural areas)
gerrymandering:
redrawing constituency boundaries to manufacture a majority vote for a certain party
legal thresholds (PR systems)
increasing the level of thresholds, raising the barrier of entry