Describe an externality for each of the following listed below. Be sure to clearly state who is harmed by it. Do not use any examples from the textbook nor the lecture videos.

NOTE: "Production" in this context means caused by the fact that something is produced and "consumption" means caused by the fact that something is consumed.

1. Positive production externality
2. Negative production externality
3. Positive consumption externality
4. Negative consumption externality