Swings in the 1975 General Election

Abstract

The 1975 General Election produced an astonishing turn-about in the state of parties in the House of Representatives. Prior to the election, Labour held 55 seats to National's 32; following it, the situation was exactly reversed. It is accordingly of more than usual interest to analyse the underlying voting swings.Such an analysis, in quantitative terms, is facilitated by the absence 01 boundary changes in the intervening years, thus eliminating a potentially major source of variation in electoral voting patterns. Changes in the distribution of the voting population through new voters, deaths and net migration, of course, remain, and none of these need be neutral as regards party. In 1975 there was the special factor of 18-year-olds being eligible to vote for the first time. Net immigration (for the country as a whole) was also unusually large in the period 1972-75. Other novel factors were the enfranchisement of aliens and the re-definition of "Maori", permitting roll transfers.Nevertheless, the fundamental hypothesis of this paper is that changes in the size and composition of electorates and in the distribution of electors between electorates as well as the qualities of individual candidates were relatively minor influences on the outcome of the 1975 General Election. Instead, it is hypothesized that the overwhelmingly important factors were nation-wide voting swings between Labour, National and Wastagethe last comprising votes for minor parties, informal votes and non-votes (so far as these can be assessed).