Hi PT and friends,
I too like the idea of 'collective kamma', which by implication is also to suggest 'collective rebirth'. But let me suspend this question of rebirth for now as I really don't wish to go down that track again.....
Buddhists like David Loy and Ken Jones, who employ Buddhist ideals for social theory, have suggested the idea of 'collective kamma'. This is the idea that the forces that impels us to enact again and again the Three Poisons of greed, ill-will and ignorance are not simply 'internal', 'individual' forces but also collective forces that can be identified in various institutional discourses and practices. It is these collective forces that generate 'collective dukkha'.
I like this idea of 'collective kamma' because it encourages a less individualistic outlook on one's Dhamma practice. As we all know, we cultivate the path to remove kilesas such as greed, hatred, ill-will, etc, etc. It is by the eradication of kilesas that we liberate ourselves from dukkha. And traditionally, kilesas have been explained as 'internal' proclivities that condition how we act, and hence, how we generate kamma.
Loy and Jones use the idea of 'collective kamma' to encourage engaged Buddhism. They formulate the term as a means to extend Dhamma practice beyond the confines of individual concern. According to this idea of 'collective kamma', what drives our actions towards greed, ill-will, etc, can be located 'externally' too. This suggests to me that if we want to eradicate kilesas, we need to also attend to how they are perpetuated 'externally' in various social discourses and practices. In other words, we need to become aware of our position in society, as a collective, to see that such kilesas are shared problems.
We talk about sankharas as the mental formations or dispositions that influence our actions. As I understand it, 'sankhara' also connotes any compounded phenomenon, from the most concrete objects such as mountains to the most abstract ideas such as Quantum Physics. So if Awakening is about understanding the nature of sankharas, shouldn't we also bring 'external' compounded phenomena (which might include anything, from our consumerist behaviour to attitudes about a particular gender/sexuality) within the scope of our practice, as our circumstances allow? Perhaps this is how we might come to really see the individual and society, self and others, as mutually constitutive?
So yes, I agree that it is fruitful to conceptualise Buddhist soteriology in a more collective fashion--this is not a subtle appeal to Mahayana ideals btw; as I have suggested above we can do this with the terms that are normally used in Theravada.