Shocked by the loss of a safe Nationalist seat to Labor, the Nationalist government was moved to initiate electoral reform and change the voting system to preferential voting (also known outside Australia as instant-runoff voting) as part of a rewrite of the electoral legislation, with the "Commonwealth Electoral Act 1918". While preferential voting had already been introduced at the state level in Western Australia (1907) and Victoria (1911) and had been considered at the federal level by Sir Joseph Cook's government (1913–1914), it was only the "considerations of partisan advantage not the finer points of electoral theory" that provided the impetus for the change.