How are points that lie on the production possibility frontier categorized?

Points that lie on the production possibility frontier (PPF) are categorized as efficient because they represent the maximum output possible from the available resources and technology. When an economy is operating on the frontier, it means it is utilizing its resources in the most productive way, with no wasted opportunities. This situation indicates that any attempt to increase the production of one good would lead to a decrease in the production of another, illustrating the concept of opportunity cost. Therefore, being on the PPF signifies that the economy is fully employing its resources efficiently, maximizing output without compromising the production of any goods.

Points inside the frontier would be deemed inefficient, as they indicate underutilization of resources. Points outside of the frontier are considered unattainable, as they represent levels of production that exceed the economy's current capabilities. The term "excessive" does not appropriately describe a situation within the context of the PPF, as it does not reflect a standard economic categorization of production efficiency.