A Hybrid Framework for Reinsurance Optimization: Integrating Generative Models and Reinforcement Learning

arXiv stat.ML / 2026/3/24

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要点

  • 提案論文は、VAEsで複数ライン・複数年の保険金データの同時分布を学習し、PPOで再保険契約条件(トリーティパラメータ)を動的に最適化するハイブリッド枠組みを提示した。
  • 期待剰余(expected surplus)を、資本制約や破綻確率(ruin-probability)制約と整合させるように目的関数を明確化し、統計モデリングと逐次意思決定を接続している。
  • シミュレーションおよびパンデミック型・カタストロフ型ショックを含むストレステストで、従来の比例型・stop-lossベンチマークよりも高い剰余と低いテールリスクを示した。
  • クロスライン依存の表現に生成モデルが有効であり、実務的な再保険設定でRLによる動的な契約設計が成立しうることを、ベンチマーク比較とともに主張している。

Abstract

Reinsurance optimization is a cornerstone of solvency and capital management, yet traditional approaches often rely on restrictive distributional assumptions and static program designs. We propose a hybrid framework that combines Variational Autoencoders (VAEs) to learn joint distributions of multi-line and multi-year claims data with Proximal Policy Optimization (PPO) reinforcement learning to adapt treaty parameters dynamically. The framework explicitly targets expected surplus under capital and ruin-probability constraints, bridging statistical modeling with sequential decision-making. Using simulated and stress-test scenarios, including pandemic-type and catastrophe-type shocks, we show that the hybrid method produces more resilient outcomes than classical proportional and stop-loss benchmarks, delivering higher surpluses and lower tail risk. Our findings highlight the usefulness of generative models for capturing cross-line dependencies and demonstrate the feasibility of RL-based dynamic structuring in practical reinsurance settings. Contributions include (i) clarifying optimization goals in reinsurance RL, (ii) defending generative modeling relative to parametric fits, and (iii) benchmarking against established methods. This work illustrates how hybrid AI techniques can address modern challenges of portfolio diversification, catastrophe risk, and adaptive capital allocation.