Olli Herrala, Aalto University
In this research, we go beyond the well-explored realm of bilevel optimization and turn our attention to models with three hierarchical levels of decision making. We present two single-level reformulations for trilevel models, along with discussion on the strengths, weaknesses and required assumptions for both reformulations. The methodological contributions are demonstrated using a case study on finding an optimal carbon tax for the Nordic electricity market. This is joint work with Steven Gabriel, Fabricio Oliveira and Tommi Ekholm.