What Is an Electoral System?
The rules that translate votes into political power, and why they matter more than most people realize.
The Rules of the Game
An electoral system is the set of rules that determines how votes are cast, counted, and converted into seats in a legislature or other elected body. These rules include the ballot structure (how voters express their preferences), the district magnitude (how many seats are elected per district), and the formula used to allocate seats based on votes. Together, these elements determine who wins power.
Electoral systems are often overlooked because they seem technical, but they are among the most consequential institutional choices a democracy makes. Two countries with identical distributions of voter preferences can produce radically different governments depending on their electoral rules. In the 2015 UK general election, UKIP won 12.6 percent of the vote but only one seat (out of 650). Under a proportional system, UKIP would have won roughly 82 seats. The rules did not just shape the outcome; they determined which voices were heard.