Voting Methods for Ranked, Rated and Approval Ballots

Implements a range of voting methods and electoral systems for determining election winners, including the D21 method with and without minus votes (Janecek, < https://www.ih21.org/en/d21-janecek-method>), first-past-the-post, two-round runoff, instant runoff, the Borda count, approval voting, majority judgement and the Condorcet method. The functions accept several ballot formats - ranking, cardinal utilities, approvals and scores - with automatic detection of the input type, configurable tie-breaking and tidy summaries of the results.

electsys21

Voting Methods for Ranked, Rated and Approval Ballots

electsys21 is an R package that determines election winners using a range of voting methods. The functions accept several ballot formats — rankings, cardinal utilities (scores) and approvals — with automatic detection of the input type, configurable tie-breaking and tidy summaries of the results.

Installation

You can install the development version from GitHub with:

# install.packages("devtools")
devtools::install_github("ivan-ih21/electsys21")

Quick start

library(electsys21)

# Generate 20 ranking ballots over 4 candidates
ballots <- gen_ranks(n_voters = 20, n_candidates = 4, seed = 1)

# Run a First-Past-The-Post election
fptp(ballots)

Every method returns a result object; print it or call summary() on it for a formatted results table.

Voting methods

Ballot formats

The voting functions accept a matrix (or data frame) with one row per voter and one column per candidate. Three input types are recognised and detected automatically (or set explicitly via type):

• rank — integer ranks, 1 = most preferred;
• utility — cardinal scores, higher = more preferred;
• approval — a logical or {0, 1} matrix.

majority_judgement() additionally accepts a score type, where each entry is treated directly as an integer grade.

The helpers gen_ranks(), gen_utilities() and gen_approvals() generate random ballots for testing and demonstration.

License

MIT © Ivan Iakimov