Nowcasting food inflation with a massive amount of online prices

The consensus in the literature on providing accurate inflation forecasts underlines the importance of precise nowcasts. In this paper, we focus on this issue by employing a unique, extensive dataset of online food and non-alcoholic beverages prices gathered automatically from the webpages of major online retailers in Poland since 2009. We perform a real-time nowcasting experiment by using a highly disaggregated framework among popular, simple univariate approaches. We demonstrate that pure estimates of online price changes are already effective in nowcasting food inflation, but accounting for online food prices in a simple, recursively optimized model delivers further gains in the nowcast accuracy. Our framework outperforms various other approaches, includ-ing judgmental methods, traditional benchmarks, and model combinations. After the outbreak of the COVID-19 pandemic, its nowcasting quality has improved compared to other approaches and remained comparable with judgmental nowcasts. We also show that nowcast accuracy increases with the volume of online data, but their quality and relevance are essential for providing accurate in-sample fit and out-of-sample nowcasts. We conclude that online prices can markedly aid the decision-making process at central banks.(c) 2022 International Institute of Forecasters. Published by Elsevier B.V. All rights reserved.

Online food prices and shocks to product availability since Covid-19

Using web-scraping, we have gathered daily data on prices and product availability for over 50,000 unique food items from 7 major retailers in Poland since January 2020. We find a 24% drop in product availability during the first COVID-19 wave in April 2020. Next, with two-step and iterative GMM applied to a variety of specifications, we show a modest price response to stockouts, as a 10% decline in food product availability leads to an immediate 0.5% rise in prices throughout the first COVID-19 wave. During the subsequent pandemic waves, this link disappears. We also detect only a 4% drop in product availability following the onset of the Russian invasion of Ukraine in February 2022, thus we suspect that the recent price movements are linked primarily to cost and demand factors. Our evidence is indicative of retailers fearing consumer anger during unorthodox times. © 2023 Informa UK Limited, trading as Taylor & Francis Group.