In "The Fall of the Roman Empire" by Michael Grant, he uses that same example (a private livestock exchange between two farmers, over their shared back fence to assure secrecy) to demonstrate how Rome in its terminal imperial stage had indeed made itself the arbiter of value of all things created, traded, bought or sold by its citizens. As Grant tells it, the farmers were obligated to locate a Roman tax collector, report the exchange and pay the requisite tax. The penalty for not reporting the transaction was death.

The difference between the collapsing Roman Empire and our devolving American one is that we already have the automated and regulatory infrastructure in place to surveil every human interaction (because: to keep us safe!), to account for every calf, lambkin, and kid (because: to determine the CO2 each creates!) and to make legible every barter transaction (because: tax reporting already applies to barter irs.gov/taxtopics/tc420).

What's missing is the death penalty piece, but with IRS SWAT teams having become a thing for what in essence is a mere administrative crime enforced by CPA's, I'm pretty sure that at the critical psychological juncture we'll all be treated to wave-after-lurid-wave of body-cam footage of accidental murders of citizens, their children and their dog (Real? Staged? DeepFake? Who knows?) in raids-gone-bad over a $12 barter transaction, until the citizenry gets the message and feels the threat. Then, when the IRS auditor is sitting in one's living room perusing his thick file in tense silence, how long will it be before a citizen wonders aloud: "Can a fellow retroactively file a 1099 on a barter he might hypothetically have forgotten to include under gross income?"

It won't be you and me, Lon. We're rocks. It'll be the other guy (our stinking, weaselly weasel of a counterparty) that turns us in. But we're caught, none-the-less. And then it's our turn to make the same deal: "This all goes away if I get ten Barter 1099's, with names I don't already have." Pretty soon the whole country will be rolled up tight by less than ten percent of its population. (The weaselly ten percent.)

Also: Dentists, barbers? Really? The Iron Rule is never barter with anyone whose rice bowl requires a license from the state. That button always gets pushed first! Right away; no exceptions. People who have lived their whole professional lives inside the velvet rope of a licensed cartel will do whatever they need to do -- without batting an eye or shedding a tear. I think we all know that by now.