[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.
Local Impact. Every business provides a good or service to a consumer or another business. The supply and demand of the good or service affects the revenue attainable from the market. Case in point: When petroleum companies increase the cost of fuel because of limited supply, it affects businesses globally and locally.