【正文】 e supply curve shifts leftward. The Number of Suppliers The larger the number of suppliers of a good, the greater is the supply of the good. An increase in the number of suppliers shifts the supply curve rightward. Supply 169。 2020 Pearson AddisonWesley Technology Advances in technology create new products and lower the cost of producing existing products. So advances in technology increase supply and shift the supply curve rightward. The State of Nature The state of nature includes all the natural forces that influence production— for example, the weather. A natural disaster decreases supply and shifts the supply curve leftward. Supply 169。 2020 Pearson AddisonWesley Figure shows an increase in supply. An advance in the technology for producing energy bars increases the supply of energy bars and shifts the supply curve rightward. Supply 169。 2020 Pearson AddisonWesley A Change in the Quantity Supplied Versus a Change in Supply Figure illustrates the distinction between a change in supply and a change in the quantity supplied. Supply 169。 2020 Pearson AddisonWesley Movement Along the Supply Curve When the price of the good changes and other influences on sellers’ plans remain the same, the quantity supplied changes and there is a movement along the supply curve. Supply 169。 2020 Pearson AddisonWesley A Shift of the Supply Curve If the price remains the same but some other influence on sellers’ plans changes, supply changes and the supply curve shifts. Supply 169。 2020 Pearson AddisonWesley Equilibrium is a situation in which opposing forces balance each other. Equilibrium in a market occurs when the price balances the plans of buyers and sellers. The equilibrium price is the price at which the quantity demanded equals the quantity supplied. The equilibrium quantity is the quantity bought and sold at the equilibrium price. ? Price regulates buying and selling plans. ? Price adjusts when plans don’t match. Market Equilibrium 169。 2020 Pearson AddisonWesley Price as a Regulator Figure illustrates the equilibrium price and equilibrium quantity. If the price is $ a bar, the quantity supplied exceeds the quantity demanded. There is a surplus of 6 million energy bars. Market Equilibrium 169。 2020 Pearson AddisonWesley If the price is $ a bar, the quantity demanded exceeds the quantity supplied. There is a shortage of 9 million energy bars. If the price is $ a bar, the quantity demanded equals the quantity supplied. There is neither a shortage nor a surplus of energy bars. Market Equilibrium 169。 2020 Pearson AddisonWesley Price Adjustments At any price above the equilibrium price, a surplus forces the price down. At any price below the equilibrium price, a shortage forces the price up. At the equilibrium price, buyers’ plans and sellers’ plans agree and the price doesn’t change until some event changes either demand or supply. Market Equilibrium 169。 2020 Pearson AddisonWesley An Increase in Demand Figure shows that when