Changes in inventories (or stocks) are defined as the difference between additions to and withdrawals from inventories. In national accounts they consist of changes in:
- stocks of outputs that are still held by the units that produced them prior to their being further processed, sold, delivered to other units or used in other ways;
- stocks of products acquired from other units that are intended to be used later for intermediate consumption or for resale without further processing;
- work in progress, which are goods being processed but not yet delivered to the user at the end of the accounting period;
- strategic stocks managed by government authorities (food, oil, stocks for market intervention).
In the national accounts changes in inventories are shown as a change in assets in the capital account.