How Taiwan's Single-Member District Two-Vote Electoral System Operates

During every election, Taiwanese voters receive more than one ballot. Since 2008, Legislative Yuan elections have adopted a "single-member district two-ballot system," which is the key to understanding the allocation of seats in Taiwan's parliament. Grasping this system is essential to understanding why certain political parties receive high vote shares yet disproportionate seat counts.

The Two-Ballot System: One Vote for a Candidate, One for a Party

The "two ballots" refer to one vote cast for a district candidate and another cast for a political party. The first ballot determines the 73 "single-member district legislators," where the candidate with the highest vote count in each district wins. This is the "single-member district" system—the winner takes all. The second ballot determines the 34 "at-large legislators," which are distributed according to the percentage of votes received by each political party.

Composition of the 113 Seats

The 113 seats in the Legislative Yuan are composed of three parts: 73 district legislators, 34 at-large legislators (nationwide at-large and overseas Chinese nationals), and 6 indigenous legislators (3 each for lowland and highland indigenous populations). This design balances local representation with proportional party distribution.

The 5% Threshold and Proportional Allocation

The allocation of at-large seats features a 5% vote threshold—a political party must cross a 5% vote share in the district and at-large ballots to qualify for at-large seat distribution. This threshold presents a severe test for minor parties and serves as an important variable in Taiwan's multi-party political landscape.

Impact of the System

Single-member districts tend to foster a two-party showdown, while small and medium-sized parties must rely on party ballots to compete for at-large seats in order to survive. This system has profoundly shaped Taiwan's party map and campaign strategies, serving as an underlying logic that cannot be ignored when observing each general election.