I was delighted to discover an example of micro-institutions at work this week right in my own backyard, er, campus. Several of my classes have been held in the Social Psychology building on Duke's West Campus. Most traffic to this building comes from the nearby Perkins library, to the southwest.

None of the sidewalks allows for the most direct route, which leads from an outdoor stairway diagonally across a small lawn. None until now, that is. This week I observed the scene in the photo: a sidewalk being put in exactly the same place as the well-worn footpath from pedestrians observing the triangle inequality. (Please forgive the poor quality of the picture.) The new sidewalk is a perfect example of a central planner responding to the emergent order of individual actions, rather than resisting it. Micro-institutions really work.