“…(Nollet and Beaulieu, 2003) Number of joint activities low med-high med low med Number of members low-med high low-med low low 7. Life span of the group (D'Aunno and Zuckerman, 1987;Johnson, 1999;Nollet and Beaulieu, 2003) Expected life span of the group low-med high high low high Note: The subdimensions are based on: gains and costs (Nollet and Beaulieu, 2003), complexity (Johnson, 1999), independency (Essig, 2000), intensiveness (Klein Woolthuis, 1999;Williams, 2005), devoted resources Nollet and Beaulieu, 2003), formalisation (Ball and Pye, 2000;Dyer and Singh, 1998;Johnson, 1999), free riding prevention (Dyer and Singh, 1998;Johnson, 1999), savings allocation mechanisms (Heijboer, 2003;Schotanus, 2005b), self-management and decentrality Williams, 2005), control (Schotanus, 2005a), joint decision making (Laing and Cotton, 1997), standardisation , committed members (Williams, 2005), coterminosity (Exworthy and Peckham, 1998), homogeneity of demand (Bakker et al, 2007;Rozemeijer, 2000), and number of members (Bakker et al, 2007;Nollet and Beaulieu, 2003). a Characteristics of subdimensions that differ from the subdimension above b Can also be defined as joint meetings, control, decisions by all members, and/or decentrality c For instance, uniformity of organisational structure, size, policy, market, and life span Based on Table 2, it is noticed that within the forms of cooperative purchasing several differences may exist.…”