What is the primary factor that causes movements along the supply curve?

The primary factor that causes movements along the supply curve is changes in price. When the price of a good or service increases, producers are typically willing to supply more of that good, leading to a movement up the supply curve. Conversely, if the price decreases, producers will supply less, resulting in a movement down the supply curve. These movements illustrate the fundamental relationship between price and quantity supplied, which is a core principle of supply theory in economics.

In contrast, changes in consumer preferences, fluctuations in production technology, and variations in government policy can affect the overall position of the supply curve, shifting it left or right, rather than causing movements along it. These factors influence how much of a good or service is offered at every price level but do not directly cause changes in the quantity supplied at a specific price.