by Jack Santucci
I just discovered several papers on the determinants of ballot invalidity (informal voting) in Australia. Two recent conversations prompted me to look for these. The overarching issue is whether an invalid ballot reflects confusion or protest voting. You can find the papers in my reference list. The answer seems to be: both but more of the latter, especially among young people dissatisfied with the party system.
Read more…This post updates a graphic I produced in June 2021. I have added data from the Australian Electoral Commission for 2018 and 2022, as well as a line indicating the adoption of compulsory voting.
Invalidity in recent years seems to hover around 5 percent. That figure is consistent with figures from research on the United States. Some of it is recent, and some of it is quite old.
Two potential explanations stand out: voter confusion and refusal to follow compulsory-ranking instructions (see especially p. 9 here).
Data for the graph are here. The data up to 2016 used to be available here.