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Michael Gabbay

Senior Principal Physicist






Dr. Gabbay's current research involves the development of mathematical models and computational simulations of network dynamics, focusing on social and political systems. He has also conducted research in the areas of nonequilibrium pattern formation, coupled oscillator dynamics, sensor development, and data analysis algorithms. His work has appeared in physics, engineering, biology, and political science publications. Dr. Gabbay received a B.A. in physics from Cornell University and a Ph.D. in physics from the University of Chicago with a specialization in nonlinear dynamics.


Ph.D. Physics, University of Chicago, 1997

M.S. Physics, University of Chicago, 1987

B.A. Physics, Cornell University, 1985


2000-present and while at APL-UW

Networks of cooperation: Rebel alliances in fragmented civil wars

Gade, E.K., M. Gabbay, M.M. Hafez, and Z. Kelly, "Networks of cooperation: Rebel alliances in fragmented civil wars," J. Conflict Resolut., EOR, doi:10.1177/0022002719826234, 2019.

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14 Feb 2019

When rebels make alliances, what informs their choice of allies? Civil wars are rarely simple contests between rebels and incumbent regimes. Rather, rival militant networks provide the context in which these fragmented conflicts unfold. Alliances that emerge within this competitive landscape have the power to alter conflict trajectories and shape their outcomes. Yet patterns of interrebel cooperation are understudied. The existing scholarship on rebel alliances focuses on why rebels cooperate, but little attention is given to the composition of those alliances: with whom rebels cooperate. We explore how power, ideology, and state sponsorship can shape alliance choices in multiparty civil wars. Employing network analysis and an original data set of tactical cooperation among Syrian rebels, we find compelling evidence that ideological homophily is a primary driver of rebel collaboration. Our findings contribute to an emerging literature that reasserts the role of ideology in conflict processes.

Fratricide in rebel movements: A network analysis of Syrian militant infighting

Gade, E.K., M.M. Hafez, and M. Gabbay, "Fratricide in rebel movements: A network analysis of Syrian militant infighting," J. Peace Res., EOR, doi:10.1177/0022343318806940, 2019.

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21 Jan 2019

Violent conflict among rebels is a common feature of civil wars and insurgencies. Yet, not all rebel groups are equally prone to such infighting. While previous research has focused on the systemic causes of violent conflict within rebel movements, this article explores the factors that affect the risk of conflict between pairs of rebel groups. We generate hypotheses concerning how differences in power, ideology, and state sponsors between rebel groups impact their propensity to clash and test them using data from the Syrian civil war. The data, drawn from hundreds of infighting claims made by rebel groups on social media, are used to construct a network of conflictual ties among 30 rebel groups. The relationship between the observed network structure and the independent variables is evaluated using network analysis metrics and methods including assortativity, community structure, simulation, and latent space modeling. We find strong evidence that ideologically distant groups have a higher propensity for infighting than ideologically proximate ones. We also find support for power asymmetry, meaning that pairs of groups of disparate size are at greater risk of infighting than pairs of equal strength. No support was found for the proposition that sharing state sponsors mitigates rebels’ propensity for infighting. Our results provide an important corrective to prevailing theory, which discounts the role of ideology in militant factional dynamics within fragmented conflicts.

Frame-induced group polarization in small discussion networks

Gabbay, M., Z. Kelly, J. Reedy, and J. Gastil, "Frame-induced group polarization in small discussion networks," Social Psychol. Q., 81, 248–271, doi:10.1177/0190272518778784, 2018.

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1 Sep 2018

We present a novel explanation for the group polarization effect whereby discussion among like-minded individuals induces shifts toward the extreme. Our theory distinguishes between a quantitative policy under debate and the discussion’s rhetorical frame, such as the likelihood of an outcome. If policy and frame position are mathematically related so that frame position increases more slowly as the policy becomes more extreme, majority formation at the extreme is favored, thereby shifting consensus formation toward the extreme. Additionally, use of a heuristic frame can shift the frame reference point away from the policy reference, yielding differential polarization on opposing policy sides. We present a mathematical model that predicts consensus policy given group member initial preferences and network structure. Our online group discussion experiment manipulated policy side, disagreement level, and network structure. The results, which challenge existing polarization theory, are in qualitative and quantitative accord with our theory and model.

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Acoustics Air-Sea Interaction & Remote Sensing Center for Environmental & Information Systems Center for Industrial & Medical Ultrasound Electronic & Photonic Systems Ocean Engineering Ocean Physics Polar Science Center