The public–private partnership (or PPP) system is widely hailed as an effective approach to flood insurance. PPP effectiveness can be empirically demonstrated through an analytic framework based on model assessment, which we apply to Japan as an illustrative case study. We first introduce the widely-observed market failure phenomenon in the catastrophe insurance sector and how PPP systems may serve to avert this failure. We then proceed to select three candidate systems and model them respectively. Subsequently, we employ empirical data and Monte Carlo simulations to evaluate suitability for Japan’s case via three perspectives. The results identified the market-oriented system as the economically-optimal choice. It should be noted, however, that the assessment is dependent on the priorities of each party and market-negotiated results. We find this methodology to be suitable for identifying the most adequate PPP system and invite policymakers to consider its use when implementing their own systems.

公私伙伴关系（或PPP）系统被广泛认为是洪水保险的一种有效方法。通过基于模型评估的分析框架，可以通过经验证明PPP的有效性，我们将其应用于日本作为说明性案例研究。我们首先介绍在巨灾保险领域广为人知的市场失灵现象，以及PPP系统如何避免这种失灵。然后，我们继续选择三个候选系统并对它们分别进行建模。随后，我们使用经验数据和蒙特卡洛模拟，通过三个角度评估日本案例的适用性。结果确定了以市场为导向的系统是经济上最优的选择。但是，应该指出的是，评估取决于各方的优先级和市场谈判的结果。