ABSTRACT
A comparison of the British and Irish electoral systems demonstrates, if proof were needed, that differences in the rules for aggregating votes into seats have a profound effect on national politics. Ireland has a system (single transferable vote) more geared to obtaining proportionality between party shares of votes and of parliamentary seats than the British (O’Leary 1979). It also offers voters more of a choice between parties and candidates. The British single-member constituencies with simple pluralities would have guaranteed Fianna Fail, with a plurality of the popular vote in most elections from 1932, a near-permanent majority government in Ireland. Under the actual system of the single transferable vote in multi-member constituencies Fianna Fail had instead often to form minority governments with outside support. Conversely the Irish system, applied to Britain, would have enforced minority or coalition government over the whole postwar period, with marked differences in party style and policies, not to mention the institutional workings of government.
