Researchers have found that pet ownership causally increases life satisfaction. The estimated benefit is valued at up to £70,000 (approximately $88,000) annually. Remarkably, this effect is comparable to the wellbeing gains associated with being married or having regular social interactions with friends and family.
To address limitations in earlier studies—particularly the problem of reverse causality—researchers Michael W. Gmeiner of the London School of Economics and Adelina Gschwandtner of the University of Kent applied an instrumental variable approach. They used a proxy variable—how often someone is asked to watch over neighbors' property—as an instrument to predict pet ownership and isolate its causal effect.
"Despite ample literature showing the association of pet companionship with human health, the evidence that this relationship is causal is not conclusive," the researchers wrote in Social Indicators Research.
"It could be that happy and healthy people decide to take a pet as a companion rather than pets making people happy and healthy."
Using data from the Innovation Panel of the U.K. Household Longitudinal Survey, the investigators estimated that pet companionship increases life satisfaction by 3 to 4 points on a 7-point scale. This result remained statistically significant after adjusting for a wide range of potential confounders, including income, physical and mental health, social capital, and the "Big Five" personality traits.
Causal Estimation Using Instrumental Variables
The instrumental variable—frequency of watching over neighbors' property—was selected based on its correlation with pet ownership and its plausibility as a factor that is unrelated to life satisfaction except through pet companionship. The researchers controlled for neighborhood cohesion to address potential confounding by social capital.
Ordinary least squares regression models, which did not account for reverse causality, showed an insignificant or slightly negative association between pet ownership and life satisfaction. In contrast, the instrumental variable models demonstrated a strong, positive, and statistically significant causal effect.
Using the life satisfaction approach to assign a monetary value to intangible benefits, the researchers estimated that pet ownership contributes up to £70,000 ($88,000) annually in life satisfaction. This estimate is in line with prior valuations of social interactions: "The value of pets for their human caregivers appears to be very high, comparable to the one that has been obtained in other studies for meeting with friends and relatives on a regular basis or even with being married," the researchers noted.
Personality Traits and Pet Ownership
The study also examined associations between personality traits and pet ownership. Compared with dog owners, cat owners scored significantly higher on openness and conscientiousness but lower on extraversion. Overall, pet owners had higher scores on openness, conscientiousness, and extraversion compared with nonpet owners.
Quantifying Psychological Benefits
The investigators noted that these findings may be useful in informing future research and discussions around the role of companion animals in human wellbeing.
No conflicts of interest were disclosed.