A news article on production of oil and natural gas in the Permian Basin of western Texas and New Mexico noted the following two facts: i. "Shale drillers in the Permian Basin are producing vast amounts of gas as a byproduct of prospecting for oil." ii. "Gas prices in parts of the prolific region hovered near zero last month and some trades went negative, to as low as a negative 25 cents per million British thermal units...." Source: Rebecca Elliott, "In Booming Oilfield, Natural Gas Can Be Free," Wall Street Journal, December 27, 2018. a. What does it mean for a price to be negative? A negative 25-cent price means that