Boundaries to justice

What constitutes a fair distribution of rights, resources and opportunities? Is it an equal distribution, in which case an equal distribution of what, precisely – resources, opportunities, welfare etc?

Principles of distributive justice apply to a set of individuals insofar as they are either:

a) interacting economically with each other, or
b) subject to the same set of coercive political institutions, or
c) bound together by a common identity.

These are all, evidently, ways in which people may be related to each other, and which in principle could be used to mark a boundary between those who are inside the relationship and those who are not.

source: David Miller, www.politics.ox.ac.uk