Hugh Pickens writes "Portland, Oregon will be the first city to use IBM's new software called Systems Dynamics for Smarter Cities, containing 3,000 equations which collectively seek to model cities' emergent behavior and help them figure out how policy can affect the lives of their citizens. The program seeks to quantify the cause-and-effect relationships between seemingly uncorrelated urban phenomena. 'What's the connection, for example, between ... obesity rates and carbon emissions?' writes Greg Lindsay. 'To find out, simply round up experts to hash out the linkages, translate them into algorithms, and upload enough historical data to populate the model. Then turn the knobs to see what happens when you nudge the city in one direction.' One of the drivers of the 'Portland Plan' is the city's commitment to a 40 percent decrease in carbon emissions by 2030, which necessitates less driving and more walking and biking. After running the model, planners discovered a positive feedback loop: More walking and biking would lead to lower obesity rates for Portlanders. In turn, a fitter population would find walking and biking a more attractive option. But as the field of urban systems gathers steam, it's important to remember that IBM and its fellow technology companies aren't the first to offer a quantitative toolkit to cities. In the 1970s, RAND built models they thought could predict fire patterns in New York, and then used them to justify closing fire stations in NYC's poorest sections in the name of efficiency, a decision that would ultimately displace 600,000 people as their neighborhoods burned."