Does Tactical Voting Matter? The Political Impact of Tactical Voting in Canadian Elections

Tactical voting primarily takes place under single-member district plurality electoral institutions and takes the form of third-party supporters voting for one of the major parties. Although much has been written about tactical voting, few studies have attempted to show its impact on seat distribution within the parliament or on the makeup of the subsequent government, in countries with single-member plurality systems. In this article, we assess the magnitude and impact of tactical voting in the Canadian general elections between 1988 and 2000. We build a model of tactical voting by identifying factors that are known to affect the level of tactical voting that we can measure using available data. Based on this model, we generate predicted levels of tactical voting for all parties within each district, and then use these predicted values to adjust the actual election data to produce a new set of data containing a would-be election outcome in the absence of tactical voting. By comparing actual election data, adjusted election data, and the seat share of political parties in the parliament after these elections, we discuss the political impact of tactical voting in Canada. The results of our study affirm that, in some cases, tactical voting does lead to election outcomes different from those in its absence and that arguments based on voter rationality are to some degree valid in the real world. At the same time, our results demonstrate that the impact of tactical voting on election outcomes, and thus on the actual distribution of seats within the parliament, has been minimal in Canada. It had no impact on the partisan composition of the government in any of the four elections studied.