Consider a ball resting at the center of the sombrero pictured at right. Poised at the very center of the sombrero and at rest, the ball will not move. It is in an (unstable) equilibrium. Nonetheless, if nudged, the ball will roll down into the ring of the sombrero. The lowest ring around the peak of the sombrero is a stable equilibrium. Any further nudges will push the ball around the ring a bit; but the ball will end up rolling around the ring from then on.

In this case, physicists would call the direction in which the ball gets nudged an "order parameter."  Starting from the peak of the sombrero, the ball will roll in any direction easily.  But starting from the ring of the sombrero, the ball will tend to roll only along tangents to the ring.  Thus, the breaking of the rotational symmetry of the order parameter signals a new equilibrium.

People, firms, and even whole markets can persist in unstable equilibriums, like the peak of the sombrero.  If it's a big enough sombrero, even relatively big nudges won't move us off the peak.  In addition, from the peak of the sombrero, every direction looks about the same.  So for a long time we might get nudged one way and then nudged back again without ever leaving the peak.

But when a group of people start seeing the sombrero rather than its peak alone, a transition can happen. That group can start rolling the ball in the same direction. It doesn't much matter what direction that is.  Any direction will do in getting us off the peak of the sombrero (so long as there isn't another group just as big trying to roll it back the other way).  Once off the peak, things will look very different to everyone, not just the people who can see the whole sombrero.  We might even be able to reach a new consensus: "We'll either go left or right around the ring.  But any other direction doesn't make sense."

We're at the peak of a sombrero in thinking about patent law in the United States right now.  We're spending tens of billions of dollars every year on new R&D.  But some of that money is spent redundantly (in ignorance of the prior art), and some of it is lost (to patent infringers) because ideas, once disclosed, are impossible to take back.  Trade secret torts and contracts just aren't as good a way to solve these problems.  Turning a blind-eye to patent infringement is bad long-term policy for the United States. There are already a few other countries that are watching and hoping that we'll drop the ball on this one. (Or I guess not push the ball far enough in the right direction.)

With the big sombrero in mind, it shouldn't be so hard for everyone to see how strong patent rights are a smart way "to promote the progress of science and the useful arts" through market-based incentives.  Both the Venetians in the 15th Century and our Founding Fathers in 1787 saw the value of patents.  Where did we go astray?

As an aside, "Broken Symmetry" is also the name for my personal blog, wherein I consider the question of what markets resemble sombreros more broadly.