Tesla CEO Elon Musk is a lot of things: pioneer and visionary to his admirers, smart aleck and stock pumper to his critics. Now, both sides can talk— and argue—about Musk the economist.

Musk put on this new hat last week during Tesla’s earnings conference call.

The numbers could have wowed. Tesla pulled off record fourth-quarter and full-year profits while growing unit volumes at almost 90%. The company’s production soared while global auto production fell roughly 10% short of projected demand.

And Musk, whatever his flaws, is the one who has built Tesla (ticker: TSLA) into a juggernaut. Today, the electric vehicle maker is the world’s most valuable auto company by a factor of roughly three.

Still, Tesla shares dropped 11.6% after the glowing numbers. It was a stock shellacking. The S&P 500 was down only 0.5%. The Dow Jones Industrial Average finished the day flat.

Musk was part of the problem. He confused investors, who were expecting the CEO to talk about cars—not economics.

“So in terms of priority of products, I think actually the most important product development we’re doing this year is actually the Optimus humanoid robot,” he said on the call. “This, I think, has the potential to be more significant than the vehicle business over time.”

Investors would have preferred to hear about a new EV model. But Musk, as ever, has bigger plans.

“If you think about the economy, the foundation of the economy is labor,” added Musk. “Capital equipment is distilled labor. So what happens if you don’t actually have a labor shortage? I’m not sure what an economy even means at that point. That’s what Optimus is about. So very important.”

After the call, in a tweet, Musk added that the economy can be as big as we want it to be, that scarcity can be abolished with a hardworking humanoid robot.

It’s quite an idea. Global annual economic output is roughly $85 trillion. But dollars are just a unit of account. The world economy is really all the technology and services that we produce and consume every day.

The world economy, or any economy, grows as companies invest in equipment and new technology that helps humans become more productive.

Optimus is new technology. To Musk, his robot can do a lot of meaningful work—driving up the output from each one of us. More output, essentially, means everyone is better off. Tesla didn’t respond to a request for comment about Musk’s economic theory.

Musk, of course, is famous for big ideas. He started both Tesla and his space company, SpaceX, essentially, to ensure human civilization can survive for thousands of years as a multiplanetary species powered by sustainable energy.

Robots playing a role in making us all better off is another big one. And it will be tough to find anyone who doesn’t think a lot more money is a bad thing.

Distributing wealthy fairly, more-or-less equitably, of course, is the trick. That’s been a problem for economist and the global economy for all of recorded history.

Musk has talked about the problem of wealth allocation, but he hasn’t offered the solution—at least not yet.