Modeling Strategy Can Help Trace Roots of Widespread Phenomena
Predicting the future is notoriously difficult, but uncovering the past can be just as tricky. Now researchers have developed a method that looks backward and may reveal where a widespread phenomenon originated, be it the outbreak of a disease or a new technology.
The new method relies on distance, but is not constrained by geography. Just as diagramming the relationships among friends can yield close or “coupled” people, even if they live far apart, diagrams of relationships among locations that consider the traffic between them can yield coupled locations. Using such relationships, researchers came up with a way to compute paths that are in effect the shortest between locations, even if they are far apart geographically. Once that path diagram is in hand, the researchers can test whether various starting points might be the root of the branching, treelike spread of whatever phenomenon is being studied. A clean, circular diagram emerges when the correct root is identified, computer simulations reveal.