The case for nil votes: Voter behavior under asymmetric information in compulsory and voluntary voting systems

In an informational voting environment, we study the impact of an explicit nil vote option on the ballot when some voters are uninformed and face the swing voters curse. We postulate a simple model of strategic voting in which voters entertain heterogeneous thresholds on legitimacy of different voting actions. We predict that introducing a nil vote option reduces the number of uninformed and invalid votes, increasing expected welfare in both voluntary and compulsory voting. We test our model in a pen-and-paper laboratory experiment, and find that the predictions of the model hold in the data, for both voting systems.