Shift-share study of inventory changes in enterprises during Covid-19

Purpose: The COVID-19 pandemic significantly impacted business operations worldwide, including in Poland. Inventory management became a key area that underwent dynamic changes due to sudden supply chain disruptions, demand variability, and logistical constraints. As a result, enterprises had to adapt their warehousing strategies to minimize risks and maintain business continuity. This study analyzes changes in inventory levels in Polish enterprises from a sectoral and regional perspective (by voivodships) between 2019 and 2023, with particular attention to the impact of the pandemic on inventory levels and structures across different economic sectors. Design/methodology/approach: The study employs the Shift-Share method to evaluate the influence of macroeconomic, industry-specific, and local factors on variations in enterprise inventories. This method allows inventory volume changes to be decomposed into components reflecting general economic trends, specific industry effects, and individual enterprise characteristics. The study analyzed inventories for three sectors: industry, trade, and construction. Each type of inventory was considered in four categories: raw materials, semi-finished products, finished products, and goods. The data were collected according to the classification of the Central Statistical Office of Poland. All data have been adjusted for inflation to ensure consistency, using 2019 as the base year. Since inflation in Poland exceeded 34% during the analyzed period, these adjustments provided accurate rates of change. Findings: Despite significant disruptions in global supply chains, the overall inventory volume in Polish enterprises increased by 19.8% between 2019 and 2023. However, the dynamics of changes varied significantly between the periods 2019–2021 and 2021–2023. The volume of most inventories increased significantly in the first period and slightly in the second. The most significant fluctuations occurred in the industrial production of raw materials and supplies. Originality/value: This study applies the Shift-Share method to analyze inventory changes across firms during the COVID-19 pandemic. It offers a sectoral and regional perspective, providing insight into the key factors influencing inventory fluctuations. The results are relevant for researchers interested in supply chain resilience and inventory management strategies during periods of economic uncertainty. Keywords: Shift-share analysis, pandemic impact, inventory. Category of the paper: Research paper, Viewpoint.