Agricultural Economics and Policy Group, ETH Zürich, Sonneggstrasse 33, 8092, Zürich, Switzerland.
Department of Agricultural Economics and Rural Development, Georg August University Göttingen, Platz der Göttinger Sieben 5, 37073, Göttingen, Germany.
Sci Rep. 2018 Jan 8;8(1):46. doi: 10.1038/s41598-017-18656-5.
Weather risks are an essential and increasingly important driver of agricultural income volatility. Agricultural insurances contribute to support farmers to cope with these risks. Among these insurances, weather index insurances (WII) are an innovative tool to cope with climatic risks in agriculture. Using WII, farmers receive an indemnification not based on actual yield reductions but are compensated based on a measured weather index, such as rainfall at a nearby weather station. The discrepancy between experienced losses and actual indemnification, basis risk, is a key challenge. In particular, specifications of WII used so far do not capture critical plant growth phases adequately. Here, we contribute to reduce basis risk by proposing novel procedures how occurrence dates and shifts of growth phases over time and space can be considered and test for their risk reducing potential. Our empirical example addresses drought risks in the critical growth phase around the anthesis stage in winter wheat production in Germany. We find spatially explicit, public and open databases of phenology reports to contribute to reduce basis risk and thus improve the attractiveness of WII. In contrast, we find growth stage modelling based on growing degree days (thermal time) not to result in significant improvements.
天气风险是农业收入波动的一个重要且日益重要的驱动因素。农业保险有助于支持农民应对这些风险。在这些保险中，天气指数保险（WII）是应对农业气候风险的一种创新工具。农民使用 WII 获得的赔偿不是基于实际产量减少，而是基于测量的天气指数（例如附近气象站的降雨量）进行补偿。经验损失与实际赔偿之间的差异，即基准风险，是一个关键挑战。特别是，迄今为止使用的 WII 规格不能充分捕捉关键的植物生长阶段。在这里，我们通过提出考虑和测试时间和空间上的发生日期和生长阶段变化的降低基准风险的新方法来减少基准风险，并测试其降低风险的潜力。我们的实证案例针对德国冬小麦生产中关键生育期（开花期）前后的干旱风险。我们找到了空间上明确的、公共的和开放的物候报告数据库，以帮助降低基准风险，从而提高 WII 的吸引力。相比之下，我们发现基于有效积温（热量时间）的生育阶段建模并没有带来显著的改进。
