Abstract We use real‐time scanner data in Great Britain during the COVID‐19 pandemic to investigate the drivers of the inflationary spike at the beginning of lockdown and to quantify the impact of high‐frequency changes in shopping behaviours and promotions on inflation measurement. Although changes in product‐level expenditure shares were unusually high during lockdown, we find that the induced bias in price indices that do not account for expenditure switching is not larger than in prior years. We also document substantial consumer switching towards online shopping and across retailers, but show this was not a key driver of the inflationary spike. In contrast, a reduction in price and quantity promotions was key to driving higher inflation, and lower use of promotions by low‐income consumers explains why they experienced moderately lower inflation. Overall, changes in shopping behaviours played only a minor role in driving higher inflation during lockdown; higher prices were the main cause, in particular through a reduced frequency of promotions.

中文翻译：

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购物行为、促销和通胀衡量的高频变化：来自大封锁的证据*

摘要 我们在 COVID-19 大流行期间使用英国的实时扫描仪数据来调查锁定开始时通胀飙升的驱动因素，并量化购物行为和促销活动的高频变化对通胀衡量的影响。尽管在锁定期间产品级支出份额的变化异常高，但我们发现不考虑支出转换的价格指数的诱发偏差并不比前几年大。我们还记录了大量消费者转向网上购物和跨零售商，但表明这不是通胀飙升的关键驱动因素。相比之下，减少价格和数量促销是推高通胀的关键，低收入消费者较少使用促销活动解释了为什么他们经历了适度较低的通货膨胀。总体而言，在封锁期间，购物行为的变化对推高通胀的作用很小；价格上涨是主要原因，特别是促销频率降低。