Electoral volatility has been used to evaluate democratic stabilisation, the strength of partisanship, and the salience of cleavage structures. The most widely cited measure of volatility is the ‘Pedersen index’ which relies on the change of aggregate party vote shares. Despite its parsimony and ease of calculation, significant shortcomings in its construction remain. For one, the index underestimates the magnitude of volatility occurring within an election due to its measurement of the total net change and not the total change. While this concern is not new, this paper demonstrates that this distinction matters insofar as the latter can distort key relationships between volatility and democratic performance. Using aggregate and survey data from 51 elections in 23 countries between 2001 and 2015, this paper demonstrates that the Pedersen index obfuscates a non-monotonic relationship between electoral volatility democratic performance, whereas total volatility accurately captures it. This finding has implications for the study of electoral volatility, democratic stabilisation and the so-called ‘crisis of democracy’.

Organisé par la Chaire de recherche en études électorales et la Chaire de recherche du Canada en démocratie électorale.

DATE : Mardi 10 mars, 12h-13h

LIEU : Salle C-4145, Pavillon Lionel-Groulx