"New political parties have regularly appeared in developed democracies around the world. In some countries, environmental issues, immigration concerns, economic decline, or regional issues have been rallying points for new political parties, while in other countries these same issues were addressed very quickly by established parties, and new parties have failed to emerge.". "Much recent research cannot explain why under certain circumstances new or neglected issues lead to the formation of new parties. This study explains the emergence of new political parties by utilizing a novel theoretical framework to demonstrate the crucial interplay between established parties and possible newcomers. Deriving testable hypotheses from a simple theoretical model, the book proceeds to a study of party formation in 22 developed democracies. New or neglected issues still appear as a driving force in explaining the emergence of new parties, but their effect is partially mediated by institutional factors, such as access to the ballot, public support for parties, and the electoral system.". "Altering Party Systems supports in part the existing theoretical work, but it also advances new insights. The theoretical model pinpoints problems of research design that are hardly addressed in the comparative literature on new political parties. These insights from the theoretical model lead to empirical tests that improve on those employed in the literature and allow for a much-enhanced understanding of the formation and the success of new parties."--BOOK JACKET.