【正文】 when all other influences on producers’ planned sales remain the same. 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 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 Increase in Both Demand and Supply An increase in demand and an increase in supply increase the equilibrium quantity. The change in equilibrium price is uncertain because the increase in demand raises the equilibrium price and the increase in supply lowers it. Predicting Changes in Price and Quantity 169。 2020 Pearson AddisonWesley Change in Supply with No Change in Demand When supply increases, there is a movement down along the demand curve. The equilibrium price falls and the equilibrium quantity increases. Predicting Changes in Price and Quantity 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 Prices of Related Goods Produced A substitute in production for a good is another good that can be produced using the same resources. The supply of a good increases if the price of a substitute in production falls. Goods are plements in production if they must be produced together. The supply of a good increases if the price of a plement in production rises. Supply 169。 2020 Pearson AddisonWesley The Law of Supply The law of supply states: Other things remaining the same, the higher the price of a good, the greater is the quantity supplied。 2020 Pearson AddisonWesley Prices of Related Goods A substitute is a good that can be used in place of another good. A plement is a good that is used in conjunction with another good. When the price of substitute for an energy bar rises or when the price of a plement of an energy bar falls, the demand for energy bars increases. Demand 169。 and the lower the price of a good, the larger is the quantity demanded. The law of demand results from ? Substitution effect ? Ine effect Demand 169。 2020 Pearson AddisonWesley 169。 2020 Pearson AddisonWesley Figure shows a demand curve for energy bars. Demand 169。 2020 Pearson AddisonWesley Figure shows an increase in demand. Because