New research conducted by the Andrew Young School of Policy Studies at Georgia State University suggests that an individual’s level of patience predicts how susceptible they may be to weight gain.
Obesity levels have made a significant jump over the past several decades. Today over a third of the U.S. population weighs in at a body mass index (BMI) of over 30—the value that indicates obesity—up from 13 percent in 1960.
Meanwhile, food costs have dwindled alongside the growth in BMI. Many researchers stress this connection as a main source of the epidemic. Greater affordability of high-calorie foods, they have found, leads people to consume more and obesity rates to rise.
Yet, BMI data suggest there are other factors to take into account says Charles Courtemanche, a professor of economics and Second Century Initiative faculty in the Atlanta Census Research Data Center Health and Risky Behavior Cluster. BMI levels have remained stable for much of the United States. Yet the BMI distribution chart displays a rift that indicates the boom in obesity concerns just one subsection of the population.
“Obesity rates are skyrocketing. That implies that we’re all gaining weight, but if you look at the distribution, that’s not what’s happening,” says Courtemanche.
“If you look at the skinniest half of the population today and fifty years ago, the BMI’s are not all that different. If you look at the heaviest, the heaviest people are a lot heavier now.”
Courtemanche, Assistant Professor Garth Heutel and Patrick McAlvanah of the Federal Trade Commission noted this gap and researched how food prices shape BMI among individuals. Their goal was to find what factors influence some individual’s responses to food prices and who responds to cheaper food with higher consumption.
“Everyone in the community is experiencing food getting cheaper, but only some people are gaining weight. Why is that the case?” asks Courtemanche.
They found that patience is a key factor in predicting weight gain.
In an article titled “Impatience, Incentives, and Obesity” (The Economic Journal, 2014), Courtemanche, Heutel and McAlvanah show how BMI levels match up to an individual’s “time preference,” a term economists use to describe how people make decisions about the future.
Time preference asks how a person trades off present and future desires. In other words, it quantifies one’s level of patience.
Courtemanche explains that impatience leads to higher consumption when food costs plummet.
“People classified as ‘impatient’ by economic methods are the people who gain substantial amounts of weight when food gets cheaper.”
In their study, the authors found that, even after controlling for well-known determinants of BMI such as gender, race, education and income, impatience stands out as a major contributor to obesity.
They also found that impatient consumers aren’t just eating more overall. A price change in fruits and vegetables had no bearing on high BMI. But a drop in the price of meats or high-calorie foods can lead to greater BMI growth.
The authors also provided evidence that their findings were driven at least partly by a special type of impatience termed “time inconsistency.”
As Heutel explains, “there are growing findings that show that people are more patient over decisions in the far future than they are over decisions in the near future. People seem to place an especially high value on the present relative to any period in the future. Economists term these preferences ‘time inconsistent’.
“Say you want to be healthy and fit in six months. On Monday you might plan to hit the gym on Wednesday and Friday, but on Wednesday you decide to skip the gym and eat a high-calorie snack. If your actions in the future conflict with your plans in the present, you are time-inconsistent.”
Time inconsistency can be characterized as the issue of “planner versus the doer,” in which self-control becomes a problem for people who want to lose the weight, but whose actions interfere with their goals.
This distinction between “rational” impatience and self-control has some important policy implications, Courtemanche suggests. “If everybody was rationally deciding how much to eat and how much to exercise, then it seems that there’s no real policy response. It’s not really an obesity epidemic. It’s just people making rational decisions that might happen to differ from your decision or my decision.”
The source of obesity becomes a problem when people struggle with the gap between their behavior and their goals. If unhealthy BMI is far from a choice, then “maybe there’s more justification for government intervention. Maybe policy could get the doers and the planners in sync,” he says.
Find the article at http://onlinelibrary.wiley.com/doi/10.1111/ecoj.12124/abstract.