Segnalazione bibliografica. West European Politics (March 2011), Vol. 34, N. 2, pp. 256-281 Autore: Ruben Ruiz-Rufino Abstract This article proposes a new way to measure proportionality using aggregated threshold functions. Electoral systems can be summarised by a single value that shows the necessary share of the total vote to win either one seat or half of the seats in parliament. The article calculates aggregate threshold values for 142 different electoral systems that were used in 525 democratic elections between 1946 and 2000. These results are also contrasted with the most commonly used indices of proportionality and turn out to be both substantively and empirically richer....

Segnalazione bibliografica. British Journal of Political Science (2011), 41: 341-361 Autore: Jay K. Dow   Abstract This study evaluates the extent of party-system extremism in thirty-one electoral democracies as a function of electoral-system proportionality. It uses data from the Comparative Studies of Electoral Systems project to estimate the extent of party-system compactness or dispersion across polities and to determine whether more proportional systems foster greater ideological divergence among parties. Electoral system characteristics most associated with party-system compactness in the ideological space are investigated. The empirics show that more proportional systems support greater ideological dispersion, while less proportional systems encourage parties to cluster nearer the centre of the electoral space. This...

Empirical election studies conclude that party elites' images with respect to competence, integrity and party unity – attributes that we label character-based valence – affect their electoral support (Stone and Simas, 2010). We compile observations of media reports pertaining to governing party elites' character-based valence attributes, and we relate the content of these reports to mass support for the governing parties. We present pooled, time-series, analyses of party support and valence-related media reports in six European polities which suggest that these reports exert powerful electoral effects during election campaigns but little effect during off-election periods. This finding, which we label the Election Period Valence Effect, is consistent with previous work concluding that citizens are also more attentive to policy-based considerations and to national economic conditions around the time of elections. These findings have implications for political representation and for understanding election outcomes.