In this study, we formulated a mathematical model for electorate demarcation in line with Taiwan’s electoral reforms, minimizing legislative seats for the main opposition party in Taipei City. The model is compared with historical election data to establish characteristics that are most contested and germane to the reform. | Yugoslav Journal of Operations Research 24 (2014) Number 1, 71-85 DOI ELECTORATE REDISTRICTING FOR A SINGLE-MEMBER DISTRICT PLURALITY, TWO-BALLOT VOTING SYSTEM: TAIWAN’S ELECTORAL REFORM Pei-Chun LIN Associate Professor, Department of Transportation and Communication Management Science National Cheng Kung University peichunl@ Tai Chiu Edwin CHENG Department of Logistics and Maritime Studies Science The Hong Kong Polytechnic University LGTcheng@ Received: February 2011 / Accepted: January 2013 Abstract: In this study, we formulated a mathematical model for electorate demarcation in line with Taiwan’s electoral reforms, minimizing legislative seats for the main opposition party in Taipei City. The model is compared with historical election data to establish characteristics that are most contested and germane to the reform. Examination of the constituency demarcation for the Seventh Legislator Election ascertains that electorate demarcation can/can not be manipulated to create electoral advantage. Demonstrable evidence of a bias toward disproportionate representation in the singlemember district plurality, two-ballot voting system ultimately attests the importance of scenario analysis before adopting new electorate systems. Keywords: Optimization, Electorate Redistricting, Breadth-First Search. MSC: 1. INTRODUCTION Prior to 2008, Taiwan’s electoral system utilized a single nontransferable vote under multi-member district system (hereafter SNTV) (Grofman, 1999). Under the 72 P. C. Lin, T. C. E. Cheng / Electorate Redistricting for a Single-Member SNTV, several elected representatives were drawn from an electorate based on existing administrative boundaries. Each voter cast just one vote, which was counted in terms of individual candidates, with several leading candidates being elected. However, representation has proved not to be truly proportional, in the sense that even a candidate winning a small number of .
