If one person's use of good x diminishes other people's use of it, then good x is one of two types of goods. What are those two types?

Free-rider Problem

A situation where individuals or entities receive the benefit of a good or service without contributing to its cost, commonly associated with public goods.

Market Failure

A situation where the allocation of goods and services is not efficient, often leading to a net social welfare loss.

Goods

Physical items produced for sale or use, characterized by their tangibility and their capacity to satisfy human wants or needs.