Ford vs. GM. Coke vs. Pepsi. Oxford vs. Cambridge. These famous rivalries remind us that the top two achievers in a given realm often compete fiercely with each other.

Now Stephen M. Garcia and Richard Gonzalez of the University of Michigan and Avishalom Tor of the University of Haifa have produced a useful series of studies on when competition between entities will exist – with findings that are relevant to all negotiators.