If we are to understand the interactions of a large number of agents, we must first be able to describe the capabilities of individual agents.

If we are to understand the interactions of a large number of agents, we must first be able to describe the capabilities of individual agents.

Unwrapping occurs when the "solution" is explicitly built into the program from the start.

With theory, we can separate fundamental characteristics from fascinating idiosyncrasies and incidental features. Theory supplies landmarks and guideposts, and we begin to know what to observe and where to act.

Looking back to data, we can see if the consequences are plausible; looking forward to theory, we can see if general principles are suggested.

From the point of view of physics, it is a miracle that [seven million New Yorkers are fed each day] without any control mechanism other than sheer capitalism.

The multiplier effect is a major feature of networks and flows. It arises regardless of the particular nature of the resource, be it goods, money, or messages.