We have analyzed the effects of a change in demand and supply both graphically and mathematically. We can also examine market changes with tabular data. Below we show tables of demand and supply quantities for various prices.

T he table labeled Original Equilibrium shows a market where the equilibrium price is 15 and the equilibrium quantity is 30. The table labeled Demand Increase gives values for demand after it shifts out, so the quantity demanded is higher at every price. This increase (shift out) in demand causes the equilibrium price to rise to 20 and the equilibrium quantity to increase to 40. Finally, on the table labeled Demand Decrease we show the effect of a shift back in demand where less is demanded at every price. This causes the equilibrium price to fall to 10 and the quantity to fall to 20.

Our tabular results confirm our graphical and mathematical analyses. When demand shifts out, equilibrium price and quantity rise, and when demand shifts back, equilibrium price and quantity fall.