[Note: The distance between cities in California (US) distance chart below is straight line distance (may be called as flying or air distance) between the two locations in California (US) calculated based on their latitudes and longitudes. This distance may be very much different from the actual travel distance.]
In drawing the demand schedule or the demand curve for a good we take income of the people as given and constant. When as a result of the rise in the income of the people, the demand increases, the whole of the demand curve shifts upward and vice versa. The greater income means the greater purchasing power.
The demand curve, which shows the relationship between the demand of a product and its price, is depicted by using a graph. Price appears on the vertical axis of the graph, while quantity goes on the horizontal axis. Certain factors affect the demand curve. The number of potential buyers that may purchase your company's products or services determines the size of the market. If the size of the market decreases, the demand curve shifts to the left, showing a higher price and fewer potential buyers.