Vyzkum volatility a proměny stranického spektra ve volbách do Poslanecké sněmovny v roce 2010

Volatility Research and Party System Changes in the 2010 Czech Elections to the Chamber of Deputies. The paper deals with the volatility scores in the Chamber of Deputies elections in the Czech Republic, calculated both for the national and regional (e.g. level of the electoral constituencies) levels. The main aim of the paper is to identify the link between gains and losses of the parties in the respective region with the volatility in this region. In case of the change of volatility calculated for the 2010 and 2006 elections, a distinctive increase of volatility is identified, although the comparison shows that the increase in volatility occurred mostly in the same regions in both elections. Volatility on the regional level is strongly connected to the losses of the parties which formed the previous government (in office 2006–2009) and to the gains of the strongest new party, TOP09. Also, three comparative calculations of volatility have been made with respect to the presence of “other” parties. We then suggest it would be a mistake to calculate volatility while omitting the category of “other” parties in the numerator, without also removing it from the denominator. In case of the remaining two types of calculation (“other” parties calculated as one bloc, and “other” parties omitted both in both the numerator and the denominator), further analyses might be required.