Commentary by Mark Wahl, CISA
Organizing principles for identity systems:
Modelling the effects of interoperability (20070616)
The ACM Conference on Electronic Commerce EC'07 paper "the role of compatibility in the diffusion of technologies through social networks" by Nichole Immorlica (Microsoft Research), Jon Kleinberg (Cornell), Tom Wexler (Cornell) and Mohammad Mahdian (Yahoo! Research) proposes a model, using contagion games, for interoperability between two or more technologies (e.g., instant messaging clients that support multiple protocols).
"While ... existing models of compatibility capture network effects in the sense that the users in the market prefer to use technology that is more widespread, they do not capture the more fine-grained network phenomenon represented by diffusion—that each user is including its local view in the decision, based on what its own social network neighbors are doing. A diffusion model that incorporated such extensions could provide insight into the structure of boundaries in the network between technologies; it could potentially offer a graph-theoretic basis for how incompatibility may benefit an existing technology, by strengthening these boundaries and preventing the incursion of a new, better technology."
In the latter case, the authors propose a model in which a community that has been divided between two technologies, locked in an equilibrium with no interoperability, could successfully survive the introduction of a third and superior technology by increasing their compatibility with each other.