People love to laugh, and economists are easy targets. As Michael Munger explains, jokes can be a great teaching tool. A classic joke at the expense of the dismal scientists runs as follows:

A chemist, a physicist, and an economist were stranded on a deserted island. They had a can of beans, but since they didn’t have a can opener, they had to devise a way to open it. After a long but fruitless discussion between the chemist and the physicist in which they concluded that pretty much anything they could do would mean losing a lot of the beans, the economist piped up, “I’ve got it! First, assume we have a can opener…”

It’s a jab at economists’ supposedly habitual overreliance on unrealistic simplifying assumptions. Sometimes, the criticism is unfair because any abstraction requires us to sacrifice realism in the interests of simplicity for purposes of clarity. “Perfect competition” might not describe real-world markets accurately, but the model still yields powerful and important insights. 

Sometimes, of course, the criticism is justified. For decades, economists have concluded their research papers with “policy implications,” assuming that omniscient, super-moral superheroes unlike anything that inhabits this planet — or at least any legislature, palace, or courthouse will be the ones implementing their policy prescriptions. “Assume we’re governed by the Justice League” isn’t too far from “assume we have a can opener.”

It suddenly struck me while opening a fresh can of coffee one morning. I don’t actually need a can opener that often. The coffee “can” is plastic, and instead of cutting it open, I simply removed a thin metallic film. No muss, no fuss, no sharp metal edges. I looked around in the pantry and saw that I could open many of our canned goods with pull tabs. These aren’t the unattainable luxuries of families in the top quintile of the income distribution, either. While showing Joan of Arc around Walmart, Bill Preston and Ted Logan would no doubt want to highlight that even the store-brand beans came with easy-open pull tabs.

Easy-to-open canned goods might look like small drops in Donald Boudreaux’s prosperity pool, but changes in packaging like these have made our lives easier and safer. Boudreaux discusses a simple example: shampoo. Laying aside for a second the fact that even to have shampoo is a modern miracle, Boudreaux writes:

The shampoo in your shower is in a plastic bottle. Fifty years ago that shampoo was likely in a glass bottle. I remember cutting my foot badly, sometime in the early 1970s, on a piece of glass from a bottle of shampoo that I had dropped and broken while I was showering. Fortunately, an inexpensive antibacterial ointment and Band-Aids ensured that the wound had no serious consequences.

When I was in fifth grade, I tripped while bringing groceries into the house. When I got up, I looked down and saw blood streaming from a fresh cut on my right wrist, thanks to one of the now-broken glass jars in the bag I was carrying. The cut wasn’t very deep, and so it wasn’t the brush with death I feared at the time, but it was not an experience I care to repeat — and it’s one my kids likely won’t have to have because so much of what used to be packaged in glass jars now comes in plastic bottles.

In “I, Pencil,” Leonard E. Read quoted G.K. Chesterton: “We are perishing for want of wonder, not for want of wonders.” Pull tabs and plastic bottles are among the innumerable wonders free people exercising free minds in free markets bring to us every day in exchange for progressively fewer fruits of our labors. It’s why we no longer need to assume a can opener. Someday, we might not even need one.