In ranked-choice elections voters cast preference ballots which provide a
voter's ranking of the candidates. The method of ranked-choice voting (RCV)
chooses a winner by using voter preferences to simulate a series of runoff
elections. Some jurisdictions which use RCV limit the number of candidates that
voters can rank on the ballot, imposing what we term a truncation level, which
is the number of candidates that voters are allowed to rank. Given fixed voter
preferences, the winner of the election can change if we impose different
truncation levels. We use a database of 1171 real-world ranked-choice elections
to empirically analyze the potential effects of imposing different truncation
levels in ranked-choice elections. Our general finding is that if the
truncation level is at least three then restricting the number of candidates
which can be ranked on the ballot rarely affects the election winner