Lithium is a mineral that is important in manufacturing batteries. As production of electric cars has increased, so has the demand for lithium. As a result, beginning in 2016, prices of lithium increased sharply relative to the prices of iron, copper, and cobalt. Many of the same firms that mine those minerals also mine lithium. In describing the problem of limited supplies of lithium, an article in the Wall Street Journal argues: “The solution is obvious: develop new mines. If lithium prices remain near current heady levels, the wait probably won’t be all that long.” Briefly explain the link the author sees between higher lithium prices and an increase in lithium production.