Inventory changes are an important indicator of supply and demand in the economy, and represent an increase or decrease in the amount of stock on hand for a particular item. In China's economy, inventory changes involve many aspects, such as raw materials, semi-finished products, finished products, etc. Inventory changes in various links will affect the operation and development of the entire economy.

Inventory changes are mainly determined by two aspects: one is the relationship between supply and demand, that is, the gap between product demand and supply; the other is production and circulation efficiency, that is, factors such as loss, quality problems, and timeliness of items during production and sales.

There are also different interpretations of the positive and negative meanings of inventory changes. If the change in inventories is positive, it means that more is being produced than demand, creating a surplus, which can lead to lower prices and slower economic growth. A negative inventory change, on the other hand, means demand is greater than production, potentially leading to higher prices and a shortage of supply.

Inventory changes are also related to the business cycle. Inventories tend to build during an economic slowdown, as demand falls and businesses build up inventories. And during an economic recovery, inventories tend to shrink as businesses deplete inventories as demand rises.

In China, inventory changes are often used to predict economic trends and formulate policy. For example, the government can monitor the inventory changes of important products such as steel, petroleum, and automobiles to understand the market supply and demand situation, and take timely regulatory measures to maintain market stability. In addition, inventory changes are also an important reference for enterprises to make production and management decisions, helping enterprises to predict demand and optimize production planning.

In general, inventory changes are an important indicator reflecting the supply and demand of the economy. It can help governments and enterprises understand market conditions, make corresponding adjustments and decisions, and promote economic stability and development.