Explanatory Factors for the Merger of Political Parties

Recently, scholars in party research have focused attention on questions of adaptation and change. This article isolates one particular phenomenon of party change—party merger—and presents a heuristic framework which seeks to explain why parties merge. The heuristic framework identifies three different types of factors that may act as catalysts for parties to merge: intra-party factors (within parties), inter-party factors (between potential merging partners), and contextual factors. These three different types of factors and their complex interplay are discussed and subsequently examined with reference to the merger process of two small Dutch Calvinist parties, the GPV and RPF, into the ChristenUnie