We study the effects of municipal mergers on voter turnout in a
difference-in-differences framework, using data from a wave of municipal
mergers in Finland in 2009. Analysing two pre-merger elections and
three post-merger elections, spanning a total of 17 years, we find that
municipal mergers decrease voter turnout by 4 percentage points in the
long run in the relatively small municipalities compared to similar
small municipalities that did not merge. As the average turnout rate
prior to merging in this group was around 69%, this is a substantial
effect. We also find that virtually nothing happens to turnout in the
municipalities that were relatively large within their merger.
Furthermore, mergers are associated with a decrease in voters’ political
efficacy and turnout decreases more in those municipalities that
experience larger decreases in efficacy.