The notion of "scarcity" reflects the idea that resources cannot be stretched to achieve all the goals that people desire. But what makes a particular resource "scarce"? If there seems to be more of it around than is needed, such as desert sand, is it scarce? If it is freely open to the use of many people at once, such as music on the radio waves, is it scarce? What about resources such as social attitudes of trust and respect? Make a list of a few resources that clearly are "scarce in economists' sense. Make another list of a few resources that are not.