In this paper, we study a budget-constrained reinsurance problem under a semi-dynamic framework, where an insurer faces a random number of claims and seeks to maximize the expected utility of terminal wealth. The occurrence times of claims are incorporated through discounting, allowing the model to capture the time value. For independent claims, we prove the optimality of stop-loss reinsurance contracts for a risk-averse insurer under a premium budget constraint. In the risk-neutral case, we derive pairwise structural properties of the deductible allocation in terms of the claim severities and occurrence times. We find that assigning the larger of two deductible levels to a stochastically larger claim whose arrival time is smaller in the Laplace-transform order is weakly preferable. Additionally, we establish a comparison among deductible allocations via the majorization order. When claims are dependent but the exact dependence structure is unknown, we characterize the worst-case dependence structure as comonotonicity and also establish the optimality of stop-loss reinsurance contracts under this worst-case scenario. Numerical examples and comparative statics based on Monte Carlo simulation are provided to illustrate the theoretical results.
Citation: Ka Chun Cheung, Xin Song, Yaodi Yong, Yiying Zhang. Budget-constrained semi-dynamic optimal reinsurance strategies[J]. Journal of Industrial and Management Optimization, 2026, 22(10): 5247-5274. doi: 10.3934/jimo.2026181
In this paper, we study a budget-constrained reinsurance problem under a semi-dynamic framework, where an insurer faces a random number of claims and seeks to maximize the expected utility of terminal wealth. The occurrence times of claims are incorporated through discounting, allowing the model to capture the time value. For independent claims, we prove the optimality of stop-loss reinsurance contracts for a risk-averse insurer under a premium budget constraint. In the risk-neutral case, we derive pairwise structural properties of the deductible allocation in terms of the claim severities and occurrence times. We find that assigning the larger of two deductible levels to a stochastically larger claim whose arrival time is smaller in the Laplace-transform order is weakly preferable. Additionally, we establish a comparison among deductible allocations via the majorization order. When claims are dependent but the exact dependence structure is unknown, we characterize the worst-case dependence structure as comonotonicity and also establish the optimality of stop-loss reinsurance contracts under this worst-case scenario. Numerical examples and comparative statics based on Monte Carlo simulation are provided to illustrate the theoretical results.
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