2.2.6—Movements and shifts in supply

A movement along supply follows a change in the good’s own price; a shift follows a change in another supply determinant.

Confusing these changes reverses the diagram and the causal explanation.

Ask whether the good’s own price changed; if not, examine costs, technology, taxes, expectations or firms.

A rise in the market price moves up the curve; a cheaper battery shifts the supply of electric vehicles right.

A change in quantity supplied is not the same as a change in supply.