The ideological and issue positions of parties are known to shape citizens’ political attitudes and voting behaviour. One important way to obtain estimates of parties’ positions is to ask experts to place parties on salient ideological dimensions. The Chapel Hill Expert Survey (CHES) has been collecting such estimates for democracies in Europe and elsewhere. CHES Canada adds to this project by providing estimates of party positions and characteristics of Canadian federal parties and provincial parties in Ontario and Quebec. This note introduces this new data source, clarifies how the data were collected and illustrates how the data can be used to (comparatively) study party politics in Canada.

In this article, we examine party positions on sovereignty issues in European countries based on an analysis of party supply. First, we develop an index of sovereignism reflecting the multidimensional articulation and differentiated emphasis put by parties on sovereignist issues. By applying the index to Chapel Hill Expert Survey (CHES) data, the analysis maps all EU member states. Second, we integrate in the analysis party- and country-level data (including the orientations of domestic public opinion). Through multivariate regression analysis we show how party ideology, contextual factors and public mood favoured the spread of party-based sovereignism in European countries.

Recent research on electoral behavior has suggested that policy-informed vote choices are frequently obstructed by uncertainty about party positions. Given the significance of clear and distinct party platforms for meaningful representation, several studies have investigated the conditions under which parties are perceived as ambiguous. Yet previous studies have often relied on measures of perceived positional ambiguity that are fairly remote from the concept, casting doubt on their substantive conclusions. This article introduces a statistical model to estimate a comprehensive measure of perceived ambiguity that incorporates the two principal factors: non-positions and positional inconsistency. The two-faces model employs issue perceptions in an item response framework to explicitly parametrize the perceived ambiguity of party positions. The model is applied to data from the Chapel Hill Expert Survey and subsequently associated with party characteristics that drive perceptions of party ambiguity. The results suggest that (a) there are notable differences between the proposed and competing measures, highlighting the need to be mindful of the intricacies of political information processing in research on perceptions of ambiguity and (b) involuntary ambiguity might be an underexplored explanation for unclear party perceptions.