Predicting Party Sizes: The Logic of Simple Electoral Systems

by Rein Taagepera

For a given electoral system, what average number and sizes of parties and government duration can we expect? Predicting Party Sizes is the first book to make specific predictions that agree with world averages. The basic factors are the numbers of seats in the assembly and in the average electoral district. While previous models tell us only the direction in which to change the electoral system, the present ones also tell us by how much they must be changed so as to obtain the desired change in average number of parties and cabinet duration. Hence, combined with known particularities of a country, they can be used for informed institutional design.

The book is useful to three types of political science students learning the basics of electoral systems and their political consequences; practitioners of politics who consider changing the electoral laws; and researchers intent on connecting electoral and party systems. The book is structured accordingly. Chapters start with advice and recipes for practicing politicians, in non-technical language. The main text gives students an overview of electoral systems, worldwide, and supplies evidence for models that tie simple electoral systems (First-Past-The-Post and List Proportional Representation) to the number and sizes of parties and government duration. Chapter appendices present derivations of these models and other more technical issues of interest to researchers.

336 pages, Hardcover

First published August 23, 2007

Reviews

[Miroslav Nemčok · Rating 5 out of 5]

It took me a year and 17 sheets of paper full of notes to finish this book. Nonetheless, it was a crazy ride which completely shifted my perception of political science and its methodology. Besides that, it made me to substantively change the way how I was trying to solve the problem chosen for my dissertation research. Yes, it is full of additional and yet/back-then unresolved questions and statements like "this has to be further empirically tested", but it is far away from degrading the value of this book. I believe that this is a must reading for every political science scholar willing to contribute to the general knowledge. For those from other social science areas, I am strongly recommending Taagepera's Making Social Sciences More Scientific.

[Steven Taylor · Rating 4 out of 5]

This book is an excellent addition to the electoral studies literature. While it is consciously written on two levels (for political scientists and for practitioners) it often is too technical for those who lack a certain level of mathematical proficiency.