Pets as substitutes for children

Definition

Pets as substitutes for children refers to the theory that pets may substitute for children in terms of consumption value, i.e., potential parents may use pets to obtain some of the consumption benefits of having children.

Note that the term substitutes could be used in either of two senses:

Substitution in the sense that people derive similar forms of consumption value from pets and children.
Substitution in the sense that reduced costs of one of the two (pets and children) would lead to increased consumption of that one and reduced consumption of the other. For instance, making a place more pet-friendly could lead to a reduction in the number of children people have.

While the truth of the theory in sense (1) strongly suggests its truth in sense (2), the implication is not certain, and its strength is unclear, because people's decision to have children may be sufficiently inelastic with respect to the consumption benefits that are substituted that it does not affect their fertility decisions much.

Consumption similarities between pets and children

Pets and children are both dependent creatures.
Pets and children both (appear to) form a strong bond of unconditional (or close to unconditional) love with the pet-owner or parent.

Consumption differences between pets and children

Parents feel more responsibility toward teaching children skills, with a fairly huge bare minimum.
Children grow to become (human) adults, passing through their teens in the process. This can be both rewarding and frustrating.
Children are a more long-term commitment.
The lifetime cost of a child is higher.
Other agencies, including neighbors, schools, local governments, etc., impose more stringent restrictions on the terms on which one can and should interact with one's children.

Investment differences between pets and children

Children, when they grow into adults, can be useful to have -- for financial, emotional, and other forms of support.
Children can have their own children (i.e., grandchildren).