A growing body of academic literature suggests that BAK is more efficient than CPNP and has the potential to send signals on on-net/off-net price discrimination whereas cost-based pricing incentivises MNOs to set off-net prices higher than on-net prices.40 This is because under BAK, the calling party and receiving party’s networks share the total costs of the call, regardless of whether the parties are on the same network, fixed or mobile. BAK recognises that theoretically both the caller and the recipient derive utility from a call in most cases, and imposes some of the cost of a call on each of the calling and receiving networks, thereby improving allocative efficiency.
http://www.accc.gov.au/content/item.phtml?itemId=991380&nodeId=8e9ba0d462c78e027e7d20cd3c0c7689&fn=MTAS%20final%20access%20determination%20discussion%20paper.pdf




