How much do parties respond organizationally to their social and institutional environments? This paper investigates the level of contemporary party organizational change and its causes. Firstly, the paper deals with the type of change and how much of it is perceived or actual. In doing so the analysis uses data gathered from official documents (the new PPDB database and the Party Law in modern Europe data base) and also original data based on evaluations from two rounds of expert surveys conducted in Europe in 2007 and 2015. We will hence be able to ascertain whether changes are more common to certain social and institutional settings across Europe, looking at newer as well as more-established democracies. Secondly, the paper looks into the causes of organizational change. The paper thus contributes theoretically and empirically to the debate between competing theories about life-cycle, system level trends and discreet change approaches which all tackle the issue of party organizational change from different perspectives in regards to both the nature and determinants of change.
