Moritz Laber

Moritz Laber

PhD Student in Network Science

Publications

For a complete list of publications see Google Scholar.

Effects of higher-order interactions and homophily on information access inequality

Laber, M., Dies, S., Ehlert, J., Klein, B., Eliassi-Rad, T.; Effects of higher-order interactions and homophily on information access inequality. Communications Physics (2025)

The spread of information through socio-technical systems determines which individuals are the first to gain access to opportunities and insights. Yet, the pathways through which information flows can be skewed, leading to systematic differences in access across social groups. These inequalities remain poorly characterized in settings involving nonlinear social contagion and higher-order interactions that exhibit homophily. We introduce a generative model for Hypergraphs with Hyperedge Homophily, a hyperedge size-dependent property, and tunable degree distribution, called the $ exttt{H3}$ model, along with a model for nonlinear social contagion that incorporates asymmetric transmission between in-group and out-group nodes. Using stochastic simulations of a social contagion process on hypergraphs from the $ exttt{H3}$ model and diverse real-world datasets, we show that the interaction between social contagion dynamics and hyperedge homophily—an effect unique to higher-order networks due to its dependence on hyperedge size—can critically shape group-level differences in information access. By emphasizing how hyperedge homophily shapes interaction patterns, our findings underscore the need to rethink socio-technical system design through a higher-order perspective and suggest that dynamics-informed, targeted interventions at specific hyperedge sizes, embedded in a platform architecture, offer a powerful lever for reducing inequality.

Shock propagation from the Russia–Ukraine conflict on international multilayer food production network determines global food availability

Laber, M., Klimek, P., Bruckner, M., Lihuaying, Y., Thurner, S.; Shock propagation from the Russia–Ukraine conflict on international multilayer food production network determines global food availability. Nature Food 4, 508–517 (2023)

Dependencies in the global food production network can lead to shortages in numerous regions, as demonstrated by the impacts of the Russia–Ukraine conflict on global food supplies. Here we reveal the losses of 125 food products after a localized shock to agricultural production in 192 countries and territories using a multilayer network model of trade (direct) and conversion of food products (indirect), thereby quantifying 108 shock transmissions. We find that a complete agricultural production loss in Ukraine has heterogeneous impacts on other countries, causing relative losses of up to 89% in sunflower oil and 85% in maize via direct effects and up to 25% in poultry meat via indirect impacts. Whereas previous studies often treated products in isolation and did not account for product conversion during production, the present model considers the global propagation of local supply shocks along both production and trade relations, allowing for a comparison of different response strategies.