Nikolaos Stavridis

Nikolaos Stavridis completed his doctorate at the Department of Mathematics and Applied Mathematics of the University of Crete, where his dissertation developed mathematical programming frameworks for equilibrium analysis in cap-and-trade emissions markets. The work formulated the market clearing problem for a multi-period emissions allowance market as a stochastic complementarity problem — combining the optimality conditions of individual firm abatement decisions with the market-wide allowance balance constraint — and established existence and uniqueness of equilibrium under regularity conditions on abatement cost functions. The dissertation derived comparative statics for the equilibrium allowance price as a function of the cap level, the banking and borrowing rules, and the distributional parameters of the abatement cost uncertainty, yielding results with direct relevance to the design and calibration of schemes such as the European Union Emissions Trading System.

Following his doctorate, Stavridis extended the equilibrium framework to a robust optimisation setting in which the regulator faces uncertainty about the distribution of firm abatement costs and seeks to choose an allowance cap that minimises worst-case welfare loss over a Wasserstein neighbourhood of the reference cost distribution. This bilevel robust programming problem — where the regulator's outer optimisation is over the cap and the inner problem is the market equilibrium — was reformulated as a single-level semi-infinite programme under convexity assumptions, yielding tractable finite-dimensional approximations and convergence guarantees for the robust optimal cap as the ambiguity set shrinks. He also investigated the continuous-time limit of multi-period banking-and-borrowing models, connecting the discrete market equilibrium to a singular stochastic control problem for the aggregate allowance inventory.

At IADU, Stavridis contributes mathematical optimisation methods to the Institute's research on climate and environmental policy for sovereign clients. His work examines the optimal design of carbon pricing schemes — including both tax and cap-and-trade variants — under uncertainty in abatement costs and climate damages, and provides the analytical foundations for evaluating the robustness and welfare properties of emissions market designs adopted by sovereign institutions. He supports IADU's advisory work on the quantitative assessment of environmental regulatory frameworks.