Impact of Electronic Voting Machines on Blank Votes and Null Votes in Brazilian Elections in 1998

Electronic voting machines were used for the first time in general elections in Brazil in 1998; in that year, some cities used this new voting method, while others continued to vote using paper ballots. Few studies have demonstrated that the rate of invalid votes for federal deputy was significantly lower in cities that used electronic voting machines. This article analyzes the frequency of null votes and blank votes for four posts-federal deputy, state deputy, the president and governor. Based on a comparison of the results from the 1998 elections with the results from previous elections (1994), the article demonstrates that electronic voting machines reduced the percentage of blank votes for federal deputy, state deputies, the president and governor. Meanwhile, null votes reduced the competition for the posts of federal deputy and state deputy; however, it increased the competition for posts with greater visibility in the Brazilian political system: the governor and president.