Abstract
The members of the Senate, the second chamber of the Czech Parliament, are elected through two rounds majority system in 81 one-seat electoral districts, one third every two years. The electoral boundaries are set by the law which stipulates they shall be changed, by an amendment, if the number of inhabitants in any district departs for more than 15% from the average.
Recently, these changes are carried out every two years shortly before the regular election is called for and the number of districts affected by a change is increasing gradually. Their extent, however, is usually very small which makes further changes necessary.
During last ten years, many districts have been changed more than once. It follows that the Samuels-Snyder index of malapportionment has increased from 0.0289 in 1996 to 0.0346 in 2010.
Moreover, during the last electoral cycle, the 15% limit was not in fact observed in 4 of 81 districts. Also criterion chosen for the district size is not an optimal one as it disregards the uneven distribution of minors and foreigners who do not have the voting right.
In fact, the percentage of minors and foreigners in various districts varies in the interval and , respectively. This affects the weight of votes in various districts accordingly.
Besides the problems with malapportionment, the law does not provide for any prevention of gerrymandering. Although there is no strong evidence of gerrymandering being used so far, at least one attempt in this respect was made in 2008.
The article analyses the law and its outcome and suggests some changes to be adopted.