How An Obscure Economics Theory Helped Me Unleash My Productivity

A 30-year project based on the law of diminishing marginal utility

Photo by Thomas Mowe on Unsplash

In 1991, I took an economics class that changed my life. My professor spoke broken English, often responded to students dismissively, and by all other accounts, did little to advance the college teaching profession. Yet, she told one impactful story that sparked an idea, one that enabled me to curb bad habits, eliminate destructive behaviors, and bulletproof myself against distractions for more than 30 years.

The lesson centered around a standard theory taught in most entry-level microeconomics courses — The Law of Diminishing Marginal Utility. It states that as the consumption of a product increases, the marginal utility derived from each additional unit declines. Utility refers to satisfaction, pleasure, or some other perceived benefit.

If that sounds like esoteric mumbo jumbo, read this explanation, paraphrasing what my professor told me more than 30 years ago.

Imagine you've just run a 10K race in 90-degree heat with no shade and no water. You cross the finish line, sweat dripping from every pore of your body. The extreme dryness of your throat creates a sandpaper-like tenderness when you swallow. You rush to the finisher's table, where volunteers fill cups of water. A sympathetic helper hands you a cup. It quenches your thirst. On a scale of 1 to 100, the drink's utility (the benefit) equals 100 because the water satisfies your overwhelming desire to quench your thirst. You grab a second cup. That, too, satisfies your craving but not quite so as that first cup. The third cup yields only modest satisfaction.

With each successive cup of water, the satisfaction decreases. By the time you drink your sixth or seventh cup of water, the utility gained from each drink reaches zero. Your stomach feels full. If you keep going, you'll reach a point where each glass results in negative utility; your stomach aches, and your electrolyte balance reaches dangerous levels.

That's the law of diminishing marginal utility. With each subsequent consumption, you gain less benefit, which could eventually lead to injury if the behavior continues.