“In economics, an externality is the cost or benefit that affects a party who did not choose to incur that cost or benefit.”—James Buchanan and W. Craig Stubblebine
The library rolled heavily into town, bearing its cargo of knowledge mundane, esoteric, and somewhere in between. Its ancient axles creaked as it slowed, executed a graceful turn through the caravanserai, and came to rest, facing the town square and the well that travelers used. The horses, dust coating their sweaty flanks, snorted in anticipation. Willem waited for his apprentice, Thomen, to descend, then leaned heavily on the youth’s shoulder as he eased himself to the ground, wincing at the pain in his hips. Once both feet were firmly on the ground, he stretched mightily, his joints emitting an alarming series of crackling noises.
“Ahhh… that’s better. Fetch me some water. I’m feeling drier than Epicurus, and half as lively.” He kicked at the dust to emphasize his point.
The youth grabbed the tin bucket that hung from the wagon’s bench seat, behind the buckboard, and ran to the well. By the time he’d returned, Willem had unfurled their banner, which lay limp in the motionless air. While Thomen had been away, a discreet crowd had gathered, curious to learn what the wagon had brought them. The sage took a long drink from the bucket, then poured the remainder over his head. “Thanks.” He ruffled the youth’s hair, then gestured at the banner with a cocked thumb. Thomen seized the dangling end, nimbly swarmed up the back of the wagon, and tied the banner’s end to the cord they’d attached there for this purpose. In letters two feet tall, it read: “Library.” Below, in lettering you had to approach to read, it said “Master Sage Willem, Oikonomist. Knowledge revealed, affordable rates.”
Without being asked, Thomen unhitched the horses and re-hitched them to one of the many posts made available for this purpose. Then he made several back-and-forth journeys with the bucket to fill the trough. While the horses drank, he hopped into the wagon like the monkey he’d been repeatedly told he resembled, but had seen only in pictures, and returned bearing blankets to wipe the sweat from their broad backs. He also bore an assortment of brushes and combs to curry the dust of the road from their sleek hides. By the time he’d finished and gone in search of hay, Willem had unstrapped his folding chair and card table from the stowage beneath the
