Summary, in English
Since political parties are collective goods, groups of people that demand new political parties face a collective action problem. Therefore, we can speak of a ?paradox of party-emergence?. Hence, it is puzzling that new parties became increasingly common in representative bodies at the Swedish local level during 1973?2002. This development provides a unique circumstance on which to test hypotheses on how, when and why collective action problems are solved. Adhering to the principle of methodological individualism, and using rational choice as point of departure, I set out to answer two research-questions: (1) Why do people create parties in the first place? (2) Why did party-creation become an increasingly popular political strategy between 1973 and 2002 in Swedish municipalities? I begin this venture by reviewing the existing literature in the field. I criticize and reject unsatisfactory approaches of party-emergence, and conversely retain and develop valuable approaches. Ultimately, three (complementary) approaches are constructed in order to answer the research-questions: The Parametric Model, The Sequential Model and The Dynamic Model. (1) ?The Parametric Model? uses the standard economic methodology of rational choice. Actors are assumed to be motivated by money, power or prestige, and they are also assumed to possess complete information about the relevant parameters. I hypothesize that changes in the potential party-entrepreneurs? relevant environment have boosted the net-benefits of party-creation, thus explaining why party-creation became an increasingly popular strategy during 1973?2002. Empirical evidence, however, does not support this assertion. Worse still, some environmental changes point in the opposite direction, which deepens the paradox of party-emergence. Then, (2) ?The Sequential Model? is constructed in order to move the analysis closer to the individual party-entrepreneurs. By modeling the sequences preceding the entrepreneurs? decision, and using this model to process-trace six cases ? chosen through the ?method of difference? ? of party-emergence, I set out to identify mechanisms that trigger party-emergence. Results indicate that ?strong emotions? such as anger and psychological incentives such as lust for revenge, mobilize actors to overcome costs and engage in high-cost political activities. ?Strong emotions? only provide an answer to the first question, but do not explain the emergence of new parties between 1973 and 2002. Hence, (3) ?The Dynamic Model? is constructed, which sets out to answer why party-creation became an increasingly popular strategy during the period 1973?2002. I analytically construct a hypothesis built on the assumption that a mechanism called ?rational imitation? is responsible for the fact that new parties became common in Swedish municipalities. The core argument is as follows: the fact that an entrepreneur creates a political party at t ? 1 inspires potential entrepreneurs in neighboring municipalities to create parties at later points in time. Although results only reveal weak evidence to support this hypothesis, the correlations cannot be ignored. In fact, since previous attempts to explain the increasing number of new parties in Sweden have been unsuccessful, and since face-to-face contacts no longer are assumed to be significant, these results are judged as the most promising for answering the second research-question.