Tactical voting in Swedish parliament elections

Abstract

The Swedish parliament elections utilize a system of proportional
representation. Although election fraud is very uncommon, there remains one
vulnerability -- tactical voting. In this report the possible effects of
geographical tactical voting is studied through simulation using data
from real elections.

The results point towards that it would be fully possible to accomplish geographical
tactical voting. They also show that the same total number of votes would not
necessary result in the same distribution of seats for the parliament parties,
it depends on how the votes are distributed across Sweden as a whole.

We conclude that the Swedish parliament election system would be vulnerable to
geographical tactical voting in its current state if votes could be moved.
The system itself should get an upgrade to a more sturdy one.