AI and the economy links, 4/15/2026

Bethany MacLean on stock market concentration; Russ Roberts and Stephen Witt on NVIDIA; Seb Krier on self-improvement of AI; Benedict Evans on OpenAI's business outlook

Bethany MacLean writes,

The seven companies are Apple, Alphabet, Amazon, Meta, Microsoft, Nvidia, and Tesla—“the Magnificent Seven,” Wall Street called them. At the close of 2025, these stocks had returned a remarkable 875 percent in 10 years. Indeed, over the last three years, they accounted for 55 percent of the market’s total returns, with the other 493 companies in the index making up the other 45 percent. Within a decade, they have skyrocketed from one-eighth the value of the S&P 500 to almost one-third.

What could go wrong? As you know, I am skeptical of OpenAI’s finances. And

On March 31, OpenAI raised an unprecedented $122 billion. Two-thirds of that money comes from Amazon ($50 billion) and Nvidia ($30 billion).

One can imagine that a collapse of OpenAI (which is not yet a publicly traded company) could bring down the stocks of the other firms in the AI space. Some of those firms, as we just saw, have direct investments in OpenAI. But there is also the psychological effect of a hypothetical collapse of AI on investors in other big tech firms.

The Russ Roberts podcast with Stephen Witt about NVIDIA and its CEO, Jensen Huang is interesting throughout. No excerpt can do it justice. But here is one:

They build all of the world’s most advanced microchips in Taiwan. It is a global manufacturing choke point. When they had to shut down their facilities for a little while during COVID [Coronavirus Disease], the entire world economy ground to a halt, basically. You couldn’t get a new car because the microchips that you needed for the car weren’t being produced on the line in Taiwan.

So it’s vitally important that this place stays open. And that’s on purpose. Morris Chang built that to build what he called the Silicon Shield surrounding Taiwan, where, if China invaded, they would cause the world economy to crash because it made it more painful for China to possess Taiwan.

Don’t comment on this one excerpt. Read the whole transcript, or listen to the whole podcast.

One of Tyler Cowen’s favorite AI pundits, Seb Krier, is now on substack. He writes,

the term ‘recursive self-improvement’ often conjures a science-fiction image of a blurry abstraction magically improving itself overnight and leading to some sort of hard take-off. The reality will be both more grounded and more profound. Because we are essentially ‘inventing the inventors’, we may well be heading toward a period of very high economic growth. Even so, I remain sceptical that this translates into a super-exponential takeoff in the wider economy within the current decade, even if model capabilities continue improving rapidly.

Benedict Evans writes,

the experience, product, value capture and strategic leverage in AI will all change an enormous amount in the next couple of years as the market develops. Big aggressive incumbents and thousands of entrepreneurs are trying to create new features, experiences and business models, and in the process try to turn foundation models themselves into commodity infrastructure sold at marginal cost. Having kicked off the LLM boom, OpenAI now has to invent a whole other set of new things as well, or at least fend off, co-opt and absorb the thousands of other people who are trying to do that.

I would say that OpenAI is probably learning very quickly what doesn’t work, and that is an advantage. When I had my web business back in the day, we watched competitors thrown money at ideas that we already had discarded. But Evans also sees other important challenges for OpenAI.

substacks referenced above: @

The AI Boom Was Great for Your 401(k). The Bust Won’t Be.