Mental Accounting

Chances are, you know somebody who has made a vow to go to the gym twice or three times a week, and even bought a gym membership, and never gets around to going.  You probably also know people who don’t put money in their company’s 401(k) plan, even though the company matches some or all of their contributions.  They’re walking away from free money!

Mental Accounting

Why do we do this?  Until recently, researchers had no idea what made us act so strangely.  But now, a few studies are helping explain how we make decisions, and the results are funny.

David Laibson, an economics professor at Harvard, has conducted research which suggests that people do fairly complex mental accounting whenever they make decisions, and count future rewards (or efforts) as half as important as present rewards or efforts.

How Does This Work?

Suppose you get up in the morning and face the decision of whether or not to go to the gym.  In your mind, the effort of putting on your sweats and driving the health club on any particular day can be given a hassle factor of 6.  The benefits (being more healthy and in better shape) can be assigned a benefits value of 8.  But the future benefit is discounted by half, so it has an effective weight, in your decision-making, of four.  Since 6 (the hassle) is greater than the benefit factor of 4 (eight divided by two), your mind decides to skip today’s workout.

In mathematical terms, Laibson says the decision to exercise today can be defined by the equation (-6) + (8/2) = -2.  The negative result means that the future benefits are not worth the immediate investment.

So why do people buy memberships in the gym in the first place?  Laibson offered an analysis of the PLAN (or resolution) to exercise, and the numbers come out very different.  The intention to go to the gym three times a week costs nothing.  The future effort of going to the gym (-6) will be discounted by half, and so will the benefits (+8).  Therefore the mental equation you use when you buy the gym membership be defined as 0 [the “cost” of planning to go to the gym three times a week] + (-6/2) + (8/2) = 1.

Planning to go to the gym is a win,” Laibson explains, “chiefly because the planning itself costs nothing.

In a confirming bit of research, two of Laibson’s students surveyed health and fitness facilities in the Boston area and found that the average cost of a gym membership is $75 a month.  Because people swipe their membership cards into the machines as they enter, there are fairly detailed records of how often members actually go.  The researchers found that the average person goes to the health club four times a month, which means the average cost per visit is $19.

But…  Laibson’s students found that these health clubs typically offered a $10 “pay per visit” rate.  Clearly, the people who bought their memberships intended to go at least twice as often as they actually did.  The mental equation around planning produced a very different outcome from the mental equation around execution.

Is there a way to change this mental accounting?  Laibson suggested that you hire a coach who will hold you accountable–adding a hassle factor if you don’t go to the gym.  Or arrange to meet a friend there three days a week, adding the hassle factor of disappointing your friend if you don’t show up.  Or, if you want to do it more positively, promise yourself that you’ll reward yourself with a fruit smoothie after you exercise, adding something positive to the mental equation.

This article was written by Bob Veres.  He writes for several national publications and publishes a monthly newsletter titled “Inside Information.”  You can find more info about him here

Photo Credit:  mjzitek

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