Differences

Sebenius (1984) makes the point that successful negotiations often hinge on differences rather than similarities. Basically, this is pretty obvious. If we're negotiating over how to divide a gold ring and a silver ring amongst ourselves, it will be easier for us to agree if I like silver and you like gold than it will be if we both prefer silver.

But Sebenius goes on to say something a little more interesting: that because of this, it's not always a good thing to do pleasant things like establishing common ground and finding points of agreement and hashing out common assumptions. It may be precisely our differing assumptions that make an agreement possible. Thus, for instance, if I have a house whose value I believe will go down, while my prospective buyer believes it will go up, we'll find it easier to come to an agreement than we would otherwise. Or let's say we're hashing out the details of a book deal; if you're publishing my book and believe it will do only moderately well, while I believe it will do quite well, a deal that gives me an unusually small advance but a very generous royalty package will leave us both eager to sign.