Final answer:
A motif is a recurring element in a story with symbolic importance, leading readers to uncover the theme. Scarcity is an economic principle describing the gap between limited resources and infinite wants, necessitating choice and prioritization.
Step-by-step explanation:
A motif in literature is a recurring element that has symbolic significance in a story. Through its repetition, a motif can help contribute to theme development, allowing readers to gain insight into the characters' world or the messages the author intends to convey. For instance, if a park frequently mentioned in a story represents a character's childhood, and later changes into a housing complex, these recurring references may illustrate the theme of growth and the inevitability of change.
Scarcity is a key concept in economics that arises because individuals and societies have unlimited wants but limited resources. Thomas Sowell emphasized that scarcity forces us to make decisions because we cannot have everything we want; there is always a trade-off. Thus, scarcity exists due to the fundamental economic problem of having endless desires in a world of finite resources.