Movement Along the Demand Curve

This diagram shows two points on the same demand curve D at the same price level \(P_0\). The first point gives quantity \(Q_0\) and the second gives a larger quantity \(Q_1\). The rightward arrow from \(Q_0\) to \(Q_1\) along the price line illustrates how we read the increased quantity at the same price.

This pattern appears when discussing demand shifts: if the entire curve shifts right (an increase in demand), then at the same price \(P_0\), consumers now want to buy \(Q_1\) instead of \(Q_0\). It also illustrates the basic skill of reading a graph: find a price on the vertical axis, move horizontally to the curve, then drop down to the horizontal axis to read the quantity.