rcvr

Recievor

This package was designed to mechanize the reproducible tabulation of Maine Ranked Choce/Instant Runoff elections. The work follows from the author's effort to independently and unofficially validate RC/IR tabulations presented by State of Maine for the three RC/IR contests. In particular, the goal was to do the following:

1. Create a mathematical model of tabulation processing rendered in the vocabulary of set theory.

2. Examine State of Maine RC/IR election rules in the context of the model.

3. Develop and implement an algorithm to independently verify (potentially) tabulations produced by the proprietary algorithm currently deployed in State of Maine RC/IR elections.

To accomplish the first two tasks, only official and publicly available sources were used to identify RC/IR tabulation rules. To avoid adopting hidden assumptions, others with potential knowledge of rules or tabulation implementations were not consulted. A "clean room" strategy likewise affords an opportunity to evaluate the independence (clarity and concision) embodied by the rules. The assumption being:

Official rules ought to be sufficient to guide a software implementation of an independent tabulator capable of reproducing Maine RC/IR tabulations.

The results of the modeling effort are provided in a separate document. Recievor has been written to accomplish the final task.

Contest database

Metadata to reconstruct elections are stored in the textfile contest_keys.txt, including filenames and URLs for downloading original cast vote record files from the Maine Office of the Secretary of State, Division of Elections (here). . Thus far, three data sets are available, including:

• June 12, 2018 - Primary Election

  • Governor - Democrat (132250 CVRs)
  • Representative to Congress District 2 - Democrat (50845 CVRs)

• November 6, 2018 - General Election

  • Representative to Congress District 2 (296077 CVRs)

Contest instances

Use rrcv::contest() to construct a contest instance, which will store metadata as attributes and edited ballot data in an underlying dataframe.

1. If original == TRUE the contest_str must be set to an object found in the contest database, as well as valid values for source, CVR_file, and alternative fields matching object.

2. If original == FALSE parameters for a folder (source =) and a list of cast vote records (CVR_files =) must be supplied when invoking rcvr::contest().

Tabulation options

Tabulation of contest instances is accomplished by rcvr::conduct_runoff(), which provides options for processing overvotes and undervotes.

For example under Maine rules, an overvote at a particular rank invalidates that choice and all subsequent choices. Other jurisdictions may ignore any or all overvotes. Under Maine rules, single undervotes are ignored but two consecutive undervotes invalidate all subsequent choice (download here). Maine law is more restrictive, with two sequential undervotes invalidating subsequent choices (here). The default for rcvr::conduct_runoff()

• sequentialU == FALSE
• max_U = 2
• sequentialO == FALSE
• max_O = 1

Retabulating Maine Elections

Rstudio can render the RMarkdown document repro.Rmd into a webpage that can be seen here. All inputs are downloaded from the State of Maine website.