Agricultural Economic and Policy Group, ETH Zürich, Zürich, Switzerland.
School of International and Public Affairs & the Earth Institute, Columbia University, New York, USA.
Sci Rep. 2020 May 13;10(1):7919. doi: 10.1038/s41598-020-64806-7.
A large literature has documented the effects of weather on agricultural yields. However, weather not only impacts the quantity produced, but also the quality of the product. Due to data limitations, the quality effects have primarily been studied using lab experiments for specific attributes, and the financial implications for farmers of a quality effect are less clear. Using a unique longitudinal micro-level data set of Swiss apple orchards that include information on both the quantity produced as well as the quality, we show that the latter can have an even larger effect on farm revenue. Ignoring the quality of the harvested product substantially biases the impact of weather extremes on agricultural income and the potential effects of climate change. Our quality measure is the orchard-year specific price shock. If an orchard gets a lower price for its specific apple variety compared to previous years and compared to other orchards in the same year, we observe the market's valuation of its inferior quality accounting for overall price movements (other orchards growing same variety that year) as well as orchard specific factors (orchard fixed effects). We find that spring frost events induce farm gate price drops and thus revenue reductions of up to 2.05% per hour of exposure.
大量文献记录了天气对农业产量的影响。然而，天气不仅影响产量，还影响产品的质量。由于数据限制，质量效应主要通过针对特定属性的实验室实验进行研究，而且农民面临质量效应的财务影响尚不清楚。本文利用瑞士苹果果园的独特纵向微观数据集，该数据集包含了产量和质量两方面的信息，结果表明，后者对农场收入的影响甚至更大。忽略收获产品的质量会严重偏置极端天气对农业收入的影响以及气候变化的潜在影响。我们的质量衡量标准是果园-年份特定的价格冲击。如果一个果园的某种苹果品种的价格低于前几年，也低于同年的其他果园，我们就会观察到市场对其劣质产品的估值，该估值考虑了整体价格变动（当年种植同一品种的其他果园）以及果园特定因素（果园固定效应）。我们发现，春季霜冻会导致农产品价格下降，因此每暴露一小时，农场的收入就会减少 2.05%。
