Compulsory voting and ethnic diversity increase invalid voting while corruption does not: An analysis of 417 parliamentary elections in 73 countries

FOTO CREDIT: Australian Electoral Commission

Voting is the most fundamental way for citizens to influence who gets to govern their country. At the same time, voting comes with certain costs for the individual, from gathering information about the different candidates all the way to the time and effort it takes to go turn up at the voting booth. Despite the meaning of voting and the costs it involves, significant numbers of people cast ‘invalid votes’. Invalid means that these votes are either blank, meaning that the person has not made their tick for any of the candidates, or they are spoilt. People spoil their votes by filling out the ballot incorrectly, by writing in candidates that do not run in their constituency or ‘none of the above’, and some spoil their ballot by drawing pictures or writing obscenities on their ballot.

In our article, published by Democratization, we report the results of a global study of invalid votes. While the motivation for individuals to cast an invalid vote might differ widely, we wanted to know whether there are systematic conditions that increase how many invalid votes are cast. But first, how widespread is the problem?

We investigate the levels of invalid voting in 417 democratic parliamentary elections in 73 countries on five continents from 1970 to 2011. Figure 1 shows these levels and how they developed over time. While there are a lot of elections with invalid votes around the 2% mark, the level is rising over time, with a growing number of elections having more than 5% of invalid votes—this means that a party of ‘invalid votes’ would win seats in the parliament. The extreme outliers are Peru in 2006—where the ‘invalid vote’ party would have won the election with 26.5%—and Ecuador in 1996 with 22.1%.


Fig. 1: Invalid voting in 417 democratic parliamentary elections.



How do we explain the levels of invalid voting? In our study, we find two dominant drivers: First, and as the upper left panel in Figure 2 shows, countries with enforced compulsory voting have much higher levels on invalid votes. This makes sense as these countries, which not only have compulsory voting but also penalize those that do not turn up, do not offer voters the option to ‘exit’ the process if they do not like what is on offer or do not understand the system. Thus, compulsory voting forces both those that (for whatever reason, lack of language skills, lack of democratic education etc.) do not know what they are doing to the ballot box, where they are more likely to make mistakes. Similarly, it forces those that (for whatever reason) do not want to vote to the ballot box, where they are likely to voice their protest.


Fig. 2: Predicted levels of invalid votes.


The second main driver for invalid votes that we identified is ethnic diversity of the society as shown in upper right panel in Figure 2. This means that the more distinct ethnic groups exist in a country, the more people cast an invalid vote. Again there might be two causes for this. On the one hand, this could be due to some of these ethnic groups being immigrant groups who might struggle with both language requirements and understanding the particular voting system in the country. On the other hand, ethnic diversity might lead to weaker social cohesion and to some ethnic groups feeling less involved in the country’s political processes. Unsurprisingly, the effect of ethnic fragmentation is further exacerbated by compulsory voting.

Finally, we also find that the level of corruption in a country can increase the level of invalid votes. Widespread corruption, being a socially very costly phenomenon, could lead to people protesting against the existing political actors and institutions and one way of expressing this protest is through profanity riddled (and thus invalid) ballots. When we first conducted this study, we assumed that corruption would be a very strong predictor for high levels of invalid votes. However, bottom left panel in Figure 2 shows the relationship between invalid votes and levels of corruption are less conclusive. Thus, voters do seem to protest but instead of sending an active message to the political elites, they choose to withdraw from the political process. When voting is compulsory, on the other hand, we find what we expected: whenever voters are forced to turn up at the ballot box, high corruption is connected to more invalid voting.

In sum, invalid votes are an increasing phenomenon and they are a problem for democracies because voters either do not understand the ballot and spoil them by mistake or voters actively voice their discontent with the politics in their country. In our study of 417 parliamentary elections all over the world, we find that compulsory voting strongly increases the levels of invalid votes by itself and also turns protest against corruptions into spoiled ballots. Furthermore, ethnic diversity is closely related to invalid votes. This finding is important because it means that ethnically diverse countries are tasked with making sure that all ethnic groups have the knowledge to meaningfully participate in elections and that all ethnic groups feel sufficiently integrated into the political system.


by Ferran Martinez i Coma and Annika Werner in October 2018



Ferran Martinez i Coma is a lecturer at the Center for Governance and Public Policy and Asia Institute at Griffith University, Brisbane (Australia). He is a member of the People, Elections and Parties research group at Griffith University. His research focuses on electoral behaviour, electoral integrity and comparative public opinion. Among others, he has published in European Journal of Political Research, Electoral Studies and Party Politics.

Annika Werner is a Research Fellow at the Center for Governance and Public Policy at Griffith University, Brisbane (Australia). Her research focuses on party behaviour, representation and public attitudes in the democracies of Europe and Oceania and has been published in journals such as the Journal of European Public Policy, International Political Science Review, Australian Journal of Political Science, German Politics and Regional & Federal Studies. She is Steering Group member of the Manifesto Project (MARPOR, former CMP) and Co-Editor of the Australian Journal of Political Science.


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