Schulze STV

rdf:langString Schulze STV

rdf:langString Schulze STV is a draft single transferable vote (STV) ranked voting system designed to achieve proportional representation. It was invented by Markus Schulze, who developed the Schulze method for resolving ties using a Condorcet method. Schulze STV is similar to CPO-STV in that it compares possible winning candidate pairs and selects the Condorcet winner. It is not used in parliamentary elections. The system is based on Schulze's investigations into vote management and free riding. When a voter prefers a popular candidate, there is a strategic advantage to first choosing a candidate who is unlikely to win (Woodall free riding) or omitting his preferred candidate from his rankings (Hylland free riding). According to Schulze, vote management is party coordination of free riding. Although Schulze STV is resistant to both types of free riding, Hylland free riding is impossible to eliminate. Schulze created a criterion known as "weak invulnerability to Hylland free riding". A method meets this criterion if it is invulnerable to Hylland free riding, except in cases where the Droop proportionality criterion would be violated. Schulze STV meets this criterion.