Recent literature has renewed interest in the stratarchical model of intraparty decision-making. In this version of party organization, the functions performed by parties are distributed among their discrete levels. The result is a power-sharing arrangement in which no group has control over all aspects of party life. Thus, the model potentially provides an antidote to the hierarchical version of organization. This article examines the principal parties in Australia, Canada, Ireland and New Zealand to test whether there is empirical evidence of stratarchy. An examination of candidate nomination, leadership selection and policy development finds strong evidence of shared authority between both levels of the party in key areas of intraparty democracy. Both levels accept that they cannot achieve their goals without the support of the other and so a fine balancing act ensues, resulting in constant recalibration of power relations. There is, however, little evidence of the commonly presented model of stratarchy as mutual autonomy for each level within discrete areas of competency. Instead, both the party on the ground and in the centre share authority within all three areas, resulting in a pattern of mutual interdependence rather than mutual autonomy.