A by-election in a single seat is not an especially costly or inconvenient affair, but is it the most appropriate way of replacing a retiring of deceased MP?
Since federation, Members of the House of Representatives who either die or retire have been replaced by a by-election. Senators, on the other hand, have been replaced by appointment by the state Governor after approval by the state Parliament, or in the case of territory senators by a joint sitting of federal parliament. This is because at the time of federation, the Senate was designed as a House to which the states sent representatives to pursue state interests, so it was thought that casual vacancies should be filled by the state. Given the great expense of a state-wide by-election, the next best thing was that the people’s representatives in the state parliament would chose the successor.
But within a very short time, however, the Senate became, and remains, a House where members are foremost party representatives, like the House of Representatives. Moreover, since the 1977 constitutional amendment, Senate vacancies must be filled by a person from the same political party as the senator being replaced. Any idea that the Senate is a states house has gone out the window.
So is the difference in replacement systems justified? Probably yes. A state-wide by-election for a single Senate vacancy would incur disproportionate costs. Moreover, such a by-election would be unfair. This is because the Senate is elected by proportional representation which means independents and minor parties getting around 10 per cent of the vote typically get a seat. If any of these senators were to die or retire a replacement based on a state-wide by-election for just that seat would be unfair because, typically, a candidate from a major party would take the seat. Further, a countback system runs into the difficulty of giving a seat to candidates who were there more to fill the ticket than to be serious contenders.
On the other hand, given the low cost of Representatives by-elections, there little cause to change the system to a party nomination, as with the Senate. The people are entitled to choose their representative.