Coco Krumme Thesis Defense
Coco Krumme Thesis Defense: "How Predictable: Modeling Rates of Change in Individual- and Population-Level Behavior"
Date and time: 
Dec 14 12 1:00pm - 3:00pm
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.