This FMM is a temporary, emergency entry specifically designed to alert readers to a situation that comes to a head on just one night of the year–Halloween. It will be replaced by a return to normal programming—the previous FMM—tomorrow.

Think Halloween is only the night when your kids become all manner of disagreeable, dangerous, and fantastic characters? It is for many kids, and for me it was a favorite annual tradition, the dressing up and the goodies. But that’s not the worst that can happen on Halloween. The unsavory and devilish assortment of ghouls, witches, wizards, zombies, princesses (evil and otherwise), Jedi knights and the rest, all set to beg their way to candy heaven, should present an even scarier perspective. On Halloween night, even the sweetest children (the fairy princess types, etc.) are transformed into characters that most of their parents would have them shun. That’s right—they become economists.

What? Yes, I said ‘economists.’ Here’s how it happens, but I must warn you that the really thoroughgoing transformation only takes place under traditional door-to-door Halloween candy gathering conditions. What I’ll call the Southern variant, whereby kids go to a mall or a church hall, community center, etc. to collect candy and play harvest-themed games doesn’t produce the same telltale economic symptoms. And forget that silly full moon thing. It’s a legend devised to distract us from what’s really happening. No, the economist in each kid only comes out when children are faced with opportunity cost–moon or no moon.

I happen to live in a neighborhood where this inevitable kids-to-economists transformation happens every year, and every year, it gets worse. You see, when I first moved here, the area was still fairly rural, or, as I liked to say, ‘on the frontiers of suburbia.’ The places to which you could quickly commute were mostly farms, and a local university. My town offered exactly two residential developments for those of us looking to park ourselves in an established community. Of those two developments, only one had houses within easy walking distance of each other. The other is designed for folks who want horses, mini farms, and the like. Alas, no headless horsemen, even on Halloween.

And now to the spookiest night of the year. Every Halloween, my kid and a few friends would make the trick-or-treat rounds by hopping in and out of our pickup truck, as one of us drove from driveway to driveway through the neighborhood. It usually took a couple of hours to traverse the main road. Unless they were visiting only immediate neighbors, practically every other family in the development made the same stop-and-go drive. Trick-or-treaters from homes along nearby county roads joined our neighborhood kids in making the rounds. In all, we had a fairly steady stream of hobgoblins during the evening hours when any normal, respectable hobgoblin would consider making a stop.

And then all that changed. The kids started to become economists. It wasn’t entirely their fault. New developments sprang up. Developments with houses so close together that it was not strictly necessary to drive children on their Halloween rounds. Suddenly, children were faced with the prospect of covering two or three times as many homes, and potentially collecting much more candy in total than they could on my street. That’s what opportunity costs will force you to do—look at the value of the next best alternative, and make your plans accordingly. Even my own neighbor’s kids started to hit the high-volume streets before returning (last) to see whether our lights were still on.

Halloween has become a sadder time, a time for sampling all of the candy in the bowl while waiting in vain for the doorbell to ring. And if you think decorations and spooky music will combat this neglect effectively–forget it. The little economists know better, and aren’t fooled by that superficial stuff, not while mountains of quick candy beckon elsewhere.

So, if you are busy this Halloween, don’t be deceived. You’ve been invaded by the little economists, whatever other disguise they try to pull off on you. They are calculating little creatures, and they know where you live.