This time at our flash talk series, CSH researchers Michaela Kaleta and Stefan Kitzler will present their ongoing projects. The online presentations will start at 3pm on January 21st, 2022.
If you would like to join the talk, please send an email to firstname.lastname@example.org.
Michaela Kaleta: “Stress-testing the Resilience of the Austrian Healthcare System Using Agent Based Simulation”
Practising physicians form the backbone of our systems to provide the population with access to healthcare. Indicators that seek to quantify the access to healthcare are often derived from metrics like number, type, or location of care providers. But it was shown that such indicators fall short of capturing structural barriers to healthcare that arise from the fact that patients do not access physicians at random. Network-derived indicators can paint completely different pictures on systemically important doctors. In our study, we use health record data to build a network of physicians and an agent-based model to simulate the consecutive removal of all doctors of a certain speciality and the re-distribution of their patients. We show that critical boundaries of healthcare provision are reached at different rates throughout the country for varying types of physicians and therefore find a regional- and speciality-specific resilience of the healthcare system.
Stefan Kitzler: “Disentangling Decentralized Finance (DeFi) Compositions”
We present the first study on compositions of Decentralized Finance (DeFi) protocols, which aim to disrupt traditional finance and offer services on top of distributed ledgers, such as the Ethereum. Starting from a ground-truth of 23 DeFi protocols and 10,663,881 associated accounts, we study the interactions of protocols and associated smart contracts from a network perspective. We find that DEX and lending protocols have a high degree centrality, that interactions among protocols primarily occur in a strongly connected component, and that known community detection cannot disentangle DeFi protocols. Therefore, we propose an algorithm to decompose a protocol call into a nested set of building blocks that may be part of other DeFi protocols. Allowing us to uncover the compositions of DeFi protocols, we apply the algorithm to our ground-truth dataset and conduct an empirical analysis finding that swaps are the most frequent building blocks. We also propose to use treemaps to visualize and explore the nested building blocks of specific DeFi protocols, allowing for the inspection of compositions. Finally, we present a broad picture of DeFi compositions by extracting and flattening the entire nested building block structure across multiple DeFi protocols. We discuss our findings in the contexts of increasing integration of DeFi services with Web technologies, cross-ecosystem interoperability, and the potential for systemic risks to emerge from highly complex financial services. Overall, our results and methods contribute to a better understanding of a new family of financial products.