Propensity-Based Measures of Electoral Volatility

Electoral volatility requires that voters' party preferences are not exclusive (at least under ceteris paribus conditions, i.e., when controlling for demographic replacement and party system change). Consequently, volatility can be estimated from survey data containing non-ipsative electoral preferences. This paper presents (1) the epistemological and methodological foundations of this approach; (2) a variety of specifications of such volatility measures, and criteria to assess their empirical relevance; and (3) a comparison with measures of volatility derived from different foundations. Empirical data from various European countries will be used to demonstrate the differences between different kinds of measures of volatility.