Prices arise from the countless acts of many individuals attempting to trade in various goods. They are an emergent phenomenon.

Each price contains a vast amount of information. The price of a gallon of gasoline, for example, incorporates everything from the weather in a far-off port to the stability of a foreign government. It tracks refinery availability in the Gulf of Mexico and emissions regulations in California, while simultaneously taking into account the increased

Clausewitz himself proposed that war could best be compared with commerce, since both are social conflicts of human interests and activities.

For example, in Uruk, Mesopotamia, the world’s first city-states were founded on the idea of the king as the good shepherd: the king protected and provided for

“toy” models of economies—simple models that are so abstract they bear little resemblance to reality.

In this sense, cities are an outstanding example of complex adaptive systems: collections of individual constituents (people, in this case) that interact in myriad ways, usually mediated by some sort of network.

This “prey-switching” behavior is common to generalist predators and turns out to be ecologically stabilizing for the whole food web. As generalists turn their attention to different prey species, the species that were getting depleted get a chance to recover, reducing the risk of extinction.

as cities grow and their networks evolve, the area or volume of the networks needed to keep them functionally connected tends to become smaller on a per capita basis. For example, in larger cities more people can share the same bus or segment of road or sewer pipe.

For example, economist George Steckel and anthropologist Jerome Rose (2002) examined health indicators for Prehispanic New World societies and found that the median health of individuals declined as societies grew more complex. This suggests social complexity emerges from mechanisms that promote coordinated behavior even if it is not in the best