This week, we learned that the interaction of supply and demand determines prices and output levels in markets. Prices and output levels change when either the demand curve or the supply curve shifts. Sometimes price and output both increase and decrease. Sometimes one increases while the other decreases.

Consider a situation where the price of a good rises when output increases.For example,lithium is used in rechargeable batteries for computers,phones,other electronic goods,and even certain cars.Demand for lithium was low as recently as the early2000's.Since then,both the price of lithium and the production of lithium have more than doubled.