- Inventory change=last period's ending inventory- the current period's ending inventory.
- Change in inventory= production of the firm during the year- sale of the firm during the year
No doubt in (1) but in (2) "production of the firm during the year- sale of the firm during the year" tells about remaining part which is unsold. How could we say unsold product is "change in inventory"?
Numerical example to this? Gross value added (GVA) = Value of sales by the firm + Value of change in inventories – Value of intermediate goods used by the firm.