Coco Krumme Thesis Defense
Coco Krumme Thesis Defense: "How Predictable: Modeling Rates of Change in Individual- and Population-Level Behavior"
Friday, December 14, 2012 | 1:00pm - 3:00pm
Host/Chair: 
Alex 'Sandy' Pentland

Coco Krumme develops methodologies to measure rates of change in individual human behavior, and to capture statistical regularities in change at the population level, in three pieces: i) a model of individual rate of change as a function of search and finite resources, ii) a structural analysis of population level change in urban economies, and iii) a statistical test for the deviation from a null model of rank churn of items in a distribution.

First, she defines two new measures of human mobility and search behavior: exploration and turnover. Contrary to expectation, exploration is open-ended for almost all individuals, and turnover can be modeled as a function of exploration. Further, exploration due to optimization can be distinguished from exploration due to a taste for variety: the latter is related to individual resources (income). Second, she finds that there exist regular relationships in the economic structure of cities, with important similarities to ecosystems. Third, she presents a new statistical test for distinguishing random from directed churn in rank ordered systems.

With a better understanding of rates of change, we can better predict where people will go, the probability of their meeting, and the expected change of a system over time. These results have important implications for city planning, the modeling of disease spread, and the prediction of individual consumer behavior. More broadly, they propose a new way of thinking about individual and system-level behavior: as characterized by predictable rates of innovation and change.