This project considers the Ranked-Choice Voting method (sometimes called Instant Runoff Voting) as applied to the 2020 Democratic primary election to be candidate for President of the United States.
Methodology
Voters are given access to a survey on the first of every month, starting May 2019.
The survey lists all major declared candidates still in the race at that time, per wikipedia.
Voters rank some, but not necessarily all of the candidates (which differs slightly from true RCV, but with a very large initial field of candidates requiring voters to distinguish all candidates would lower the response rate).
Candidates are ranked as follows:
Each candidate's first place votes are totaled.
The candidate with the lowest total is removed.
This candidate is stricken from all the ballots, and every voter's ballot is reranked without this candidate (any other candidate ranked higher stays as is, any other candidate ranked lower has their rank moved up by one).
This process is repeated.
For ties:
The order of elimination in the case of a tie can affect later rounds of elimination (for example, if two candidates tie for elimination but one receives a large number of second place votes on the others' ballots, they may escape elimination in subsequent rounds).
So, in the case of a tie, two (or more) scenarios are created, one where each candidate is eliminated.
The process continues in each branch (potentially branching again).
At its conclusion, this process produces a number of total rankings equal to the number of branches.
The candidates are reported as finishing first in the according percentage of branches. The candidate with the largest percentage is declared the winner.