Established par ties that engage in high levels of institutional strat egies should be able to maintain their sys temic dominance more effect ively than those that choose not to engage in these strat egies. However, the evid ence may not sup port this hypo thesis. The cartel thesis addresses the potential for challenges to the cartel to emerge as a result of par ties engaging in cartel-like beha vi our ‘ceas(ing) to be effect ive channels of communication from civil soci ety to the state’ (Katz and Mair 1995: 23). Katz and Mair argue that although estab lished par ties can create institutions that favour their own inter ests, as in France and Greece, ‘attempts at exclusion may prove counter-productive, offering to the excluded neophytes a weapon with which to mobilise the sup port of the disaffected’ (Katz and Mair 1995: 24). This was a point raised in section 2.6 and is discussed further in Chapter 6. Although estab lished par ties that engage in high levels of institutional strat egies should prove to be the more successful in terms of maintaining sys temic dominance, the restrictive sys tems put in place may ultimately prove to be counter-productive. Chapter 6 tests these hypotheses and examines the sys temic effect of the different strat egies engaged in by estab lished parties. In order to test the impact of these strat egies on the sys temic positions of western Euro pean estab lished polit ical par ties, a meas ure of exactly how this impact can be meas ured needs to be de veloped, to determine how the success or failure of estab lished par ties should be meas ured and how party sys tem change can be assessed. For answers to many of these questions, the work of Peter Mair provides a vital starting point.