Explain the principle of scarcity and how it applies to people as well as countries

The Principle of Scarcity is clearly manifested when a product, good or service of low or less supply has an undeniably high demand. A mismatch between the high demand and low supply happens. Naturally, the price of a scarce good/product/ services rises until there is already enough supply to balance the demand. In this case, people will have to conduct their own cost-benefit analysis in order to determine which among the scarce/goods/services are to be prioritized. On the other hand, the countries must also prepare measures to answer the rising economic problems if ever scarcity occurs. It is about time to think and create of alternatives.