Proceedings of the 2017 International Conference of The Computational Social Science Society of the Americas, 2017
This paper summarizes priority challenges for social and behavioral modeling based on a recent st... more This paper summarizes priority challenges for social and behavioral modeling based on a recent study building on a base of prior studies. Our focus is less on describing and hand- wringing about the current state than on identifying what is necessary for moving on. Some of the obstacles reflect inherent challenges: social systems are complex adaptive systems; they often pose "wicked problems;" and even the structure of social systems shows emergent behavior. Other obstacles reflect disciplinary norms and practices, mindsets, and numerous very difficult scientific and methodological challenges. We discuss challenges in six groups: (1) tightening links among theory, modeling, and both empirical and computational experimentation; (2) seeking more general and coherent theories while retaining alternative perspectives and narratives, and while effectively confronting multidimensional uncertainty from the outset; (3) assuring that explanatory models represent science faithfully, to include addressing aspects and determinants of behavior that have often been omitted or treated with hard-wired representations; (4) challenging experimenters to find new theory-informed (but not theory-imposing) ways to obtain and analyze relevant data in this modern era of ubiquitous data; (5) challenging theorists and technologists to provide related methods and tools; and (6) nurturing the rest of the ecology needed for overall effectiveness. We suggest identifying several national challenge problems and, for each, having a distributed and virtual social and behavioral laboratory to stimulate synthetic interdisciplinary work. These should feature mixed methods (not just classic simulation) and competition, but also frameworks, modularity, and problem-focused composition---again with competition and evolution--- rather than an imagery of standing "correct" federations. Experience shows that breakthroughs often occur as the result of solving concrete problems and then recognizing more general patterns.
Understandably and perhaps inevitably, the ever more urgent effort to comprehend the causes of vi... more Understandably and perhaps inevitably, the ever more urgent effort to comprehend the causes of violence in Iraq has so far relied on familiar conceptions. The conflict occurring there is variously described as an insurgency, a civil war, and a manifestation of global terrorism. Standard religious and ethnic categories are used to identify the participants and impute their motives. It is becoming evident, however, that the pattern of violence reflects not only a collision of organized purposes but more fundamentally a profound disintegration of Iraq’s social fabric, a process that exposes innocent victims but also limits the capacity of predators. Violence resulting from the breakdown of legal order does not have the same character as that which occurs between managed opponents. Better understanding of that distinction is likely to be one of the more important lessons to be learned.
We use mobile device data to construct empirical interpersonal physical contact networks in the c... more We use mobile device data to construct empirical interpersonal physical contact networks in the city of Portland, Oregon, both before and after social distancing measures were enacted during the COVID-19 pandemic. These networks reveal how social distancing measures and the public’s reaction to the incipient pandemic affected the connectivity patterns within the city. We find that as the pandemic developed there was a substantial decrease in the number of individuals with many contacts. We further study the impact of these different network topologies on the spread of COVID-19 by simulating an SEIR epidemic model over these networks and find that the reduced connectivity greatly suppressed the epidemic. We then investigate how the epidemic responds when part of the population is vaccinated, and we compare two vaccination distribution strategies, both with and without social distancing. Our main result is that the heavy-tailed degree distribution of the contact networks causes a targ...
Civil violence is a complex and often horrific phenomenon whose characteristics have varied by er... more Civil violence is a complex and often horrific phenomenon whose characteristics have varied by era, setting, and circumstance. Its objective analysis has rarely been feasible at spatial and temporal scales great enough and resolutions fine enough to reveal patterns useful in prevention, intervention, or adjudication. An extraordinary data set simultaneously meeting scale and resolution criteria was collected during conflict in Guatemala from 1977 through 1986. Reported here is its spatial-temporal analysis; reported as well is a putatively novel method for estimating power-law exponents from aggregate data. Analysis showed that the relationship between ethnic mix and killing was smooth yet highly nonlinear, that the temporal texture of killings was rough, and that the distribution of killing-event sizes was dichotomous, with nongenocidal and genocidal conflict periods displaying Zipf and non-Zipf distributions, respectively. These results add statistical support to claims that the G...
Proceedings of the 2017 International Conference of The Computational Social Science Society of the Americas, 2017
This paper summarizes priority challenges for social and behavioral modeling based on a recent st... more This paper summarizes priority challenges for social and behavioral modeling based on a recent study building on a base of prior studies. Our focus is less on describing and hand- wringing about the current state than on identifying what is necessary for moving on. Some of the obstacles reflect inherent challenges: social systems are complex adaptive systems; they often pose "wicked problems;" and even the structure of social systems shows emergent behavior. Other obstacles reflect disciplinary norms and practices, mindsets, and numerous very difficult scientific and methodological challenges. We discuss challenges in six groups: (1) tightening links among theory, modeling, and both empirical and computational experimentation; (2) seeking more general and coherent theories while retaining alternative perspectives and narratives, and while effectively confronting multidimensional uncertainty from the outset; (3) assuring that explanatory models represent science faithfully, to include addressing aspects and determinants of behavior that have often been omitted or treated with hard-wired representations; (4) challenging experimenters to find new theory-informed (but not theory-imposing) ways to obtain and analyze relevant data in this modern era of ubiquitous data; (5) challenging theorists and technologists to provide related methods and tools; and (6) nurturing the rest of the ecology needed for overall effectiveness. We suggest identifying several national challenge problems and, for each, having a distributed and virtual social and behavioral laboratory to stimulate synthetic interdisciplinary work. These should feature mixed methods (not just classic simulation) and competition, but also frameworks, modularity, and problem-focused composition---again with competition and evolution--- rather than an imagery of standing "correct" federations. Experience shows that breakthroughs often occur as the result of solving concrete problems and then recognizing more general patterns.
Understandably and perhaps inevitably, the ever more urgent effort to comprehend the causes of vi... more Understandably and perhaps inevitably, the ever more urgent effort to comprehend the causes of violence in Iraq has so far relied on familiar conceptions. The conflict occurring there is variously described as an insurgency, a civil war, and a manifestation of global terrorism. Standard religious and ethnic categories are used to identify the participants and impute their motives. It is becoming evident, however, that the pattern of violence reflects not only a collision of organized purposes but more fundamentally a profound disintegration of Iraq’s social fabric, a process that exposes innocent victims but also limits the capacity of predators. Violence resulting from the breakdown of legal order does not have the same character as that which occurs between managed opponents. Better understanding of that distinction is likely to be one of the more important lessons to be learned.
We use mobile device data to construct empirical interpersonal physical contact networks in the c... more We use mobile device data to construct empirical interpersonal physical contact networks in the city of Portland, Oregon, both before and after social distancing measures were enacted during the COVID-19 pandemic. These networks reveal how social distancing measures and the public’s reaction to the incipient pandemic affected the connectivity patterns within the city. We find that as the pandemic developed there was a substantial decrease in the number of individuals with many contacts. We further study the impact of these different network topologies on the spread of COVID-19 by simulating an SEIR epidemic model over these networks and find that the reduced connectivity greatly suppressed the epidemic. We then investigate how the epidemic responds when part of the population is vaccinated, and we compare two vaccination distribution strategies, both with and without social distancing. Our main result is that the heavy-tailed degree distribution of the contact networks causes a targ...
Civil violence is a complex and often horrific phenomenon whose characteristics have varied by er... more Civil violence is a complex and often horrific phenomenon whose characteristics have varied by era, setting, and circumstance. Its objective analysis has rarely been feasible at spatial and temporal scales great enough and resolutions fine enough to reveal patterns useful in prevention, intervention, or adjudication. An extraordinary data set simultaneously meeting scale and resolution criteria was collected during conflict in Guatemala from 1977 through 1986. Reported here is its spatial-temporal analysis; reported as well is a putatively novel method for estimating power-law exponents from aggregate data. Analysis showed that the relationship between ethnic mix and killing was smooth yet highly nonlinear, that the temporal texture of killings was rough, and that the distribution of killing-event sizes was dichotomous, with nongenocidal and genocidal conflict periods displaying Zipf and non-Zipf distributions, respectively. These results add statistical support to claims that the G...
Uploads
Papers by Tim Gulden