In sustainable portfolio management, categorizing assets as “brown“ or “green“ based solely on ESG ratings can be misleading. A positive ESG score does not inherently indicate environmental responsibility unless it is evaluated relative to a meaningful benchmark. We propose a rescaled ESG rating system that measures each asset’s environmental standing relative to a threshold set by policymakers, reflecting the urgency of the current climate crisis. In this system, assets are assigned positive scores if they exceed the threshold (green) and negative scores if they fall below it (brown), enhancing the interpretability of sustainability metrics in portfolio construction. However, a challenge arises when aggregating these scores into an overall portfolio rating. Under sustainable portfolio optimization developed in [11], short positions in brown assets, otherwise effectively betting against polluting companies, can paradoxically improve the portfolio’s sustainability score. This creates a misleading incentive structure. To address this, we introduce a constraint that prohibits short positions in brown assets, ensuring that such investments do not positively impact the portfolio’s sustainability rating. While this restriction better aligns with environmental objectives, it also introduces complexity into the optimization process. To resolve this, we present an intuitive algorithm inspired by the active set method, which we refer to as Green Portfolio Optimization, capable of handling these constraints efficiently even in high-dimensional settings.

The purpose of this paper is to reflect on the CONNECT 2025 Symposium in Neum, Bosnia and Herzegovina, from the angle of a junior organizer and a lecturer. We share our journey from the Western Balkans toward academic and research paths in the EU, beginning with CONNECT in 2017 and continuing through studies, research, and PhD work in Germany. Along the way, we highlight why studying abroad matters, what it teaches beyond formal education, and how these experiences can be brought back to strengthen local communities. The contribution also summarizes two accompanying lectures on AI in Science and Gender and Science in the Western Balkans, linking personal experience with broader scientific and societal themes.

In this reflection, I share my journey from being a participant in the first Connect Symposium in 2017 to returning as a junior organizer and lecturer in 2025. What began as a formative experience during my undergraduate studies became a turning point in my academic path, guiding me through a PhD and deeper engagement with the European research landscape. The symposium offered far more than lectures — it introduced me to the importance of science communication, regional cooperation, and networking, all of which shaped my career. Eight years later, I return to Neum alongside a student colleague I met during that first Connect, now ready to pass on what we once received. As we focus this year on “Towards the EU Research Area,” I hope our stories and experiences will inspire a new generation to see science not just as a profession, but as a shared, cross-border endeavor.

Since August 2022 customers have to be asked if they are interested in sustainable investment when entering a pension contract. Hence, the provider has to be prepared to offer suitable investment opportunities. Further, the provider has to manage the new risks and chances of those assets in the whole portfolio. We therefore especially look at possible consequences for optimal portfolio decisions of a life insurer and suggest modeling approaches for the evolution of the demand and the sustainability ratings for sustainable assets. We will solve various portfolio problems under sustainability constraints explicitly and suggest further research topics. As a special feature for a life insurer, we particularly look at the role of the actuarial reserve fund and the annual declaration of its return.