# Math Geek Mom: Pet Rocks (and Such)

Looking for trends that were more than a craze.

## By

February 16, 2017

In a recent class in Microeconomics, I found myself explaining how a change in tastes could affect the demand for a good. To illustrate this concept, I drew upon the idea of “pet rocks,”  which were popular when I was a teen. When I mentioned these to my students, they, mostly millennials, looked at me like I had lost my sanity. “But there are rocks everywhere, why would you pay for one?” Indeed, that was a good question, but the example seemed to get the point across, especially when I coupled it with the memory of “Beanie Babies” from the 1990s, something that some of their older siblings has collected, even if none of them ever thought of such stuffed animals as a means to early retirement. I was particularly pleased when graduates of my Macroeconomics class were able to tell me that the Beanie Baby craze was an example of a “bubble.”

The experience of having them look at me with complete disbelief led me to remember other crazes from the recent and not so recent past. They all understood the example of elastic wristbands that formed shapes when taken off, as many of them had collected such bands as children. I know that we must still have a plastic bag of those bands stuffed in a drawer somewhere, as my daughter once collected them, along with all of the neighborhood children. Those same neighborhood children also delved head first into collecting and trading Pokémon cards, printed cards that were valued (in terms of exchangeability) by the picture that appeared on them. This was before “Pokémon Go” put people at risk as they walked along city streets staring down at their cell phones.

I didn’t go on with examples, although I suppose I could have. There were Cabbage Patch dolls that my parents lined up to buy for my little sister. She, a “preemie” herself, received a “preemie” Cabbage Patch doll one year for Christmas. And then there were “mood rings,” pieces of “jewelry” that changed color based on the body temperature of the wearer. I had a necklace that was of the same material as a “mood ring,” but I have long since forgotten where it can be found.

And don’t forget “Barney,” the purple dinosaur that seemed to enchant every child under the age of eight. As a Flintstone lover, I never really understood its allure. However, he seemed to work its magic on any child that was lucky enough to be able to spend some time watching him on television. I remember when the elastic wristbands- turned-into-recognizable-shape craze exploded, many people said that they wished they had been the one to come up with that idea. Alas, I am afraid that I will not get rich that way.

I think back on many “crazes” that have come around over the years, and I am amazed that I didn’t fall prey to any of the truly negative ones. Recently, pediatricians in the U.S. have come out against “co-sleeping” with infants, even though a baby book I was given when my daughter was an infant encouraged just such a practice. And how do we, in academia, know when something is a craze and something is actually a good approach to education? I recall “MOOCS” from only a few years ago that were supposed to positively disrupt how education happened. I am glad that I did not toss my notes from my face to face classes in the recycling bin as quickly as it would seem was appropriate when that craze took off.

Indeed, this week, the lottery in this part of the country is approaching three hundred million dollars, and, as can be expected, people are creating pools to buy tickets for this lottery. I refuse to join such pools, noting, as many have also realized, that “the lottery is a tax on people who don’t understand math.”

And so, I leave you with the question. Readers, what crazes do you recall from recent years, and which did you participate in? And how do you, as a professor, distinguish between a truly positive change in direction and something that is nothing more than a craze?

+ -