Proposed changes to the electoral law resulting from amendments to the 'opposition agreement' in 2000 and their possible consequences

Amendments to the 'opposition agreement' signed by the Czech Social Democratic and the Civic Democratic Parties in early 2000, include "The Agreement on the Basic Parameters of the Change to the Electoral System". The key change in the electoral law included the increase in the number of electoral districts from 8 to 35 and the introduction of a new system for the translation of votes into seats. The article combines the proposed parameters of the bill with the data on party support from opinion polls and estimations of voting patterns known from previous elections for modelling possible electoral outcome in terms of seats. The model shows that the proposed electoral system tends to bring about unstable results in terms of seats. Even a small change in party popular support can result in a fundamental change in the number of seats obtained. Consequently, prior to an election it is extremely difficult to estimate, which parties might be able to constitute a parliamentary majority, even if relatively precise and reliable results of opinion polls are available. The proposed system rewards bigger parties and tends to punish smaller parties. It indirectly increases the threshold necessary for obtaining seats to around 10-12% of the vote.