Planet Money had a good episode on this about a year ago. Audio -> https://www.npr.org/sections/money/2018/07/13/628894815/episode-853-peak-sand https://www.np

Planet Money had a good episode on this about a year ago. Audio -> https://www.npr.org/sections/money/2018/07/13/628894815/episode-853-peak-sand https://www.npr.org/sections/money/2018/07/13/628894815/epis... Transcript -> https://www.npr.org/templates/transcript/transcript.php?storyId=628890875 https://www.npr.org/templates/transcript/transcript.php?stor...