Unfair district maps make some votes count more than others. Gerrymandering is often talked about, but rarely in concrete terms. It's widely known as the practice of drawing district boundaries to give one political party an advantage, but its effects on individual voters can feel abstract or invisible. This project aims to make those effects easier to see and understand by estimating the cost per effective vote — a measure of how much representational value is lost due to unfair redistricting.
Public election data is combined with official district boundary maps to calculate the efficiency gap, a widely used metric in political science. This metric measures the difference in "wasted votes" between parties. Wasted votes include all ballots cast for losing candidates, as well as excess votes for winners beyond what was needed to win. A consistent imbalance in wasted votes is a strong sign of partisan bias in the way districts are drawn.
To make this distortion more tangible, each wasted vote is assigned a symbolic dollar value. While not representing an actual financial cost, this approach helps illustrate how gerrymandering undermines the impact of individual votes. The total cost is calculated by multiplying the number of wasted votes by this notional value.
From there, the cost per effective vote is determined by dividing the total cost by the number of votes that directly contributed to electing a representative. This provides a way to compare how efficiently votes are converted into representation across different states.
An interactive map displays the estimated cost per effective vote for all 50 states. States are color-coded by cost, and users can explore detailed breakdowns — such as the efficiency gap and vote counts — by clicking or hovering over each state.
The dollar values shown are meant to help make a structural issue more concrete, not to imply literal economic loss! We're working on possibly expanding the tool to include historical comparisons, simulate the effects of redistricting reforms, or estimate policy consequences tied to underrepresentation. The goal is to make gerrymandering easier to see, compare, and eventually solve!