Spring is here, and Yakov and his uncle would like to go fishing for the weekend in Florida. Yakov could either go to the river in town where anyone can fish without a permit, or he could drive up to a stream located on his family's property in the countryside to fish. Assume that, no matter where people fish, all of the fish that are caught would be kept (that is, there is no "catch and release" policy).

Answer: The fishes in the river are considered rival in consumption and non excludable whereas the fish in the private stream are rival in consumption and excludable.

Question:

The fishes in the river are considered (non rival in consumption / rival in consumption) and (excludable / non excludable) whereas the fish in the private stream are (non rival in consumption / rival in consumption) and (excludable / non excludable).

Explanation:

Rivalry in Consumption means that one person consuming a good or service reduces the amount available for others to consume. In the question above, when Yakov catches a fish, it reduces the number of fishes available to others. This creates rivalry in consumption.

Excludability: is the ability to prevent potential consumers from consuming a good or service. The river in town is non excludable as anyone in town can fish there while the stream on his family's property is excludable because it is likely only the family has access to it or limits those who have access.

An example of a non excludable, non rivalrous product is street light.