排名错误的地方：意大利与欧洲的脆弱性评估、洪水损失与风险分担

中文摘要 AI 辅助

洪水发生前，政府决定在哪里投资于防护；洪水发生后，政府决定补偿多少损失。欧盟通过一个综合指数来为第一个决策提供信息，该指数对每个次国家单元进行脆弱性排名。本文通过比较2005年至2024年间遭受同一洪水的意大利省份来检验该排名。已发布的指数并未按照省份遭受的损失进行排序，无论是否控制灾害、暴露度和收入（相关系数ρ介于-0.06和0.09之间）。问题在于其权重设置。如已发布的那样，该指数主要衡量经济发展，而损失则随水而来：损失集中在共享同一流域的省份群体中反复出现，且超过一半的排名误差存在于这些群体之间。在一项预先注册的测试中，该指数及其八个竞争指数在2010年至2020年的每个预测起点被重建，该指数在分配者提出的两个问题上均排名最后。关于损失将落在何处，其排名前十的省份捕获了后续损失的16%，低于随机抽取的水平；意大利的公共洪水风险图（不考虑损失）捕获了44%。关于同一场水谁损失更多，其与后续损失的等级相关系数为0.03；其自身组件在根据过去损失重新加权后达到0.42。两种修复都不需要新数据。排名错误的损失由地方支付。在2013-2022年记录的123亿欧元中，85%未由国家转移支付覆盖，而以防洪资金（按同样方式评分）的表现并不比随机好。由于相关损失在国界内聚集，欧洲的国家级池需要比同等规模的跨境池多39%的准备金。该指数在1142个欧洲单元中以同样的方式失效，而修复措施在那里较弱。

英文摘要

Before a flood, governments decide where to invest in protection; after it, how much of the loss to compensate. The European Union informs the first decision with a composite index that ranks every subnational unit by vulnerability. This paper tests the ranking by comparing Italian provinces struck by the same flood between 2005 and 2024. The published index does not order provinces by the losses they suffer, with or without controls for hazard, exposure and income ($ρ$ between -0.06 and 0.09). The failure lies in what it weights. As published, the index mostly measures economic development, while losses follow water: they arrive in recurring groups of provinces that share a river basin, and more than half of the ranking error lies between those groups. In a pre-registered test that rebuilds it and eight rivals at every forecast origin from 2010 to 2020, the index comes last on both questions an allocator asks. On where damage will land, its top ten provinces capture 16 per cent of later damage, less than a random draw; Italy's public flood hazard map, blind to losses, captures 44. On who loses more from the same water, its rank correlation with later losses is 0.03; its own components, reweighted on past losses, reach 0.42. Neither repair needs new data. The misranked loss is paid locally. Of EUR 12.3 billion recorded over 2013-2022, 85 per cent was not covered by national transfers, and prevention funding, scored the same way, does no better than chance. Because correlated losses cluster within borders, national pools in Europe need 39 per cent more reserve than cross-border pools of the same size. The index fails the same way across 1,142 European units, where the repairs are weaker.

发表机构

• Scuola Superiore Sant’Anna（圣安娜高等学院）
• University of Pisa（比萨大学）

机构由 AI 辅助整理，请以论文原文为准。