Voting Methods & Social Choice: Plurality, Borda, Instant Runoff & Condorcet

What you'll build

What you will be able to do

Each lab ends with a concrete result that you build yourself and the checker confirms, cell by cell.

• Read a ranked-ballot profile for a park vote, count the voters, compute each ballot type's share and count how often each option is ranked first and last.
• Count first-place votes, find the plurality winner, measure its lead and check how far it is from a real majority.
• Pick the two finalists with LARGE, send every ballot to the finalist it ranks higher, count the second round and name the runoff winner.
• Build a candidate × rank table of votes, turn it into Borda scores with SUMPRODUCT, name the Borda winner and compare points per voter.
• Run an instant-runoff count round by round: tally, eliminate the weakest option, move its ballots to the next choice, and repeat until a winner is left.
• Turn every ballot into positions, build the 4 × 4 pairwise matrix, count each option's head-to-head wins and find the Condorcet winner.
• Turn rankings into approval ballots (approve the top k), count each option's approvals and share of voters, and name the approval winner.
• Line up the six methods on the same 288 ballots, name every winner, count how many different winners there are and chart first places against Borda points.