• Should the system for electing MPs be changed?
• What should replace it?
• What system should be used for an elected second chamber?

With the prospects of a hung Parliament increasing; the Commons voting for a referendum on changing the current “first past the post” system in 2011; and all three major parties now seemingly committed to a wholly or largely elected House of Lords; the review could not be timelier.

Professor Ron Johnston from the University of Bristol and co-author of the report said: ‘There is no perfect electoral system.  In our discussion we outline the trade-offs that have to be made when choosing one.’

Choosing an Electoral System identifies the characteristics of the main types of electoral system – and their variations – now used around the world, and discusses their implications for electors and political parties. The outcomes from their application, both in the UK and elsewhere, are used to illustrate their characteristics.

First-past-the-post has long been the method for electing MPs, but a number of different electoral systems have been introduced in the UK in recent decades - in elections for the European Parliament, the Scottish Parliament, the Welsh and Northern Irish Assemblies, the London Assembly, the Mayor of London and local governments in Scotland and Northern Ireland.

While voters who use these different systems generally appreciate their nature and are able to apply them with little difficulty, appreciation of the variety of systems on offer is not widespread among voters who have not experienced them, and there are many myths about their different effects on government formation and other aspects of political behaviour.  Many of those myths are dispelled once people become accustomed to using the systems and appreciating what they deliver.

Social scientists have done a great deal of research on those effects. That body of work is summarised in the report as part of the Academy’s programme of bringing the results of academic research into the public domain – with the aim of strengthening informed debate of the choices involved in selecting a voting system.

The report establishes three criteria against which electoral systems should be judged: whether they produce a parliament whose members represent particular territorial constituencies; whether their outcomes are commensurate with the concept of proportional representation; and whether electors are able to choose candidates within as well as between parties.

The report provides an accessible, non-technical introduction to electoral systems, how they operate and their outcomes relative to those criteria and trade-offs. It provides an essential introduction to an important contemporary issue for both commentators and participants, illustrating the value of public investment in the high quality social science for which the UK is renowned.