through education and work experience. Human capital differs from the classic kind in that you can’t inherit it, and it can only be rented, not bought or sold.”
“Unless you count slavery,” Art said.
Fort’s forehead wrinkled. “This concept of natural capital actually resembles the traditional definition more than human capital. It can be owned and bequeathed, and divided into renewable and nonrenewable, marketed and nonmarketed.”
“But if everything is capital of one sort or another,” Amy said, “you can see why people would think that one kind was substitutable for another kind. If you improve your manmade capital to use less natural capital, isn’t that a substitution?”
Fort shook his head. “That’s efficiency. Capital is a quantity of input, and efficiency is a ratio of output to input. No matter how efficient capital is, it can’t make something out of nothing.”
“New energy sources…” Max suggested.
“But we can’t make soil out of electricity. Fusion power and self-replicating machinery have given us enormous amounts of power, but we have to have basic stocks to apply that power to. And that’s where we run into a limit for which there are no substitutions possible.”
Fort stared at them all, still displaying that primate calm that Art had noted at the beginning. Art glanced at his lectern screen. “Natural capital— human capital— traditional capital— energy vs. matter— electric soil— no substitutes please—” He grimaced and clicked to a new page.
Fort said, “Unfortunately, most economists are still working within the empty world model of economics.”
“The full world model seems obvious,” Sally said. “It’s just common sense. Why would any economist ignore it?”
Fort shrugged, made another silent circumnavigation of the room. Art’s neck was getting tired.
“We understand the world through paradigms. The change from empty world economics to full world economics is a major paradigm shift. Max Planck once said that a new paradigm takes over not when it convinces its opponents, but when its opponents eventually die.”
“And now they aren’t dying,” Art said.
Fort nodded. “The treatments are keeping people around. And a lot of them have tenure.”
Sally looked disgusted. “Then they’ll have to learn to change their minds, won’t they.”
Fort stared at her. “We’ll try that right now. In theory at least. I want you to invent full world economic strategies. It’s a game I play. If you plug your lecterns into the table, I can give you the starting data.”
They all leaned forward and plugged into the table.
The first game Fort wanted to play involved estimating maximum sustainable human populations. “Doesn’t that depend on assumptions about lifestyle?” Sam asked.
“We’ll make a whole range of assumptions.”
He wasn’t kidding. They went from scenarios in which Earth’s every acre of arable land was farmed with maximum efficiency, to scenarios involving a return to hunting and gathering; from universal conspicuous consumption, to universal subsistence diets. Their lecterns set the initial conditions and then they tapped away, looking bored or nervous or impatient or absorbed, using formulas provided by the table, or else supplying some of their own.
It occupied them until lunch, and then all afternoon. Art had always enjoyed games, and he and Amy always finished well ahead of the others. Their results for a maximum sustainable population ranged from one hundred million (the “immortal tiger” model, as Fort called it) to thirty billion (the “ant farm” model).
“That’s a big range,” Sam noted.
Fort nodded, and eyed them patiently.
“But if you look only at models with the most realistic conditions,” Art said, “you usually get between three and eight billion.”
“And the current population is about twelve billion,” Fort said. “So, say we’re overshot. Now what do we do about that? We’ve got companies to run, after all. Business isn’t going to stop because there’s too many people. Full world economics isn’t the end of economics, it’s just the end of business as usual. I want Praxis to be ahead of the curve on this. So. It’s low tide, and I’m going back out. You’re welcome to join me. Tomorrow we’ll play a game called Overfull.”
With that he left the room, and they were on their own. They went back to their rooms, and then, as it was close to dinner time, to the dining hall. Fort was not there, but several of his elderly associates from the night before were; and joining them tonight was a crowd of young men and women, all of them lean, bright-faced, healthy-looking. They looked like a track club or a swim team, and more than half were women. Sam and Max’s eyebrows shot up and down in a simple Morse code, spelling “Ah ha! Ah ha!” The young men and women ignored that and served them dinner, then returned to the kitchen. Art ate quickly, wondering if Sam and Max were correct in their suppositions. Then he took his plate into the kitchen and started to help at the dishwasher, and said to one of the young women, “What brings you here?”
“It’s a kind of scholarship programme,” she said. Her name was Joyce. “We’re all apprentices who joined Praxis last year, and we were selected to come here for classes.”
“Were you by chance working on full world economics today?”
“No, volleyball.”
Art went back outside, wishing he had got selected to their programme rather than his. He wondered if there was some big hot tub facility, down there overlooking the ocean. It did not seem impossible; the ocean here was cool, and if everything was economics, it could be seen as an investment. Maintaining the human infrastructure, so to speak.
Back in the residence, his fellow guests were talking the day over. “I hate this kind of stuff,” said Sam.
“We’re stuck with it,” Max said gloomily. “It’s join a cult or lose your job.”
The others were not so pessimistic. “Maybe he’s just lonely,” Amy suggested.
Sam and Max rolled their eyes and glanced toward the kitchen.
“Maybe he always wanted to be a teacher,” Sally said.
“Maybe he wants to keep Praxis growing ten percent per year,” George said, “full world or not.”
Sam and Max nodded at this, and Elizabeth looked annoyed. “Maybe he wants to save the world!” she said.
“Right,” Sam said, and Max and George snickered.
“Maybe he’s got this room bugged,” Art said, which cut short the conversation like a guillotine.
The days that followed were much like the first one. They sat in the conference room, and Fort circled them and talked through the mornings, sometimes coherently, sometimes not. One morning he spent three hours talking about feudalism—how it was the clearest political expression of primate dominance dynamics, how it had never really gone away, how transnational capitalism was feudalism writ large, how the aristocracy of the world had to figure out how to subsume capitalist growth within the steady-state stability of the feudal model. Another morning he talked about a caloric theory of value called eco-economics, apparently first worked out by early settlers on Mars; Sam and Max rolled their eyes at that news, while Fort droned on about Taneev and Tokareva equations, scribbling illegibly on a drawing board in the corner.
But this pattern didn’t last, because a few days after their arrival a big swell came in from the south, and Fort cancelled their meetings and spent all his time surfing or (it turned out he did both) skimming over the waves in a birdsuit, which was a light broad-winged bodysuit, a flexible fly-by-wire hang-glider that translated the proper motions into successful flight. Most of the young scholarship winners joined him in the air, swooping around like