Final answer:
An event that occurs outside of a system and affects third parties who are not involved in the market transaction is termed an externality. These impacts, which can be either positive or negative, are also known as spillovers. The correct answer to the question is option 2) external event.
Step-by-step explanation:
The type of event that occurs outside of a system and has an effect on third parties who are not directly involved in a transaction is known as an externality. In a business context, externality refers to the impact of a market transaction on individuals or entities that are not a party to the transaction itself. Such impacts can be either positive or negative and are often referred to as spillovers because they spill over the main parties involved to affect others.
An example of an externality would be a concert producer organizing an outdoor concert that could be heard from a nearby neighborhood. Those who buy the concert tickets and the sellers enjoy their voluntary exchange, but the residents in the neighborhood experience either a positive or negative impact depending on whether they like or dislike the music. The residents have no part in the transaction between the concert-goers and the producers, yet they are affected, illustrating the concept of externalities in a market exchange.
Therefore, the correct option for the type of event that occurs outside of the system is called a(n) external event, as it arises from the externalities of market exchanges.