As I write, US stocks are plunging. I have no idea what will be happening by the time you read this post. However, stepping back from the moment, what does it mean that Wall Street indexes rose after Trump won the 2024 election but fell last week? Or that Ukrainian government bond prices rose from October 2024 until last week and then fell rapidly?

One view is that markets have wisdom–or at least predictive value–because they aggregate information from many people. Investors think critically and rigorously because their money is on the line. The recent trends make sense on their face and confirm that markets are rational.

A different view is that capitalism involves a class struggle, and capital markets rise when the upper classes expect their interests to prevail. This model has no trouble explaining why business leaders, including registered Democrats, would tell Steven Rattner that they like Trump. They were not predicting prosperity for all but expecting to profit for themselves.

I would endorse a third model. Friedrich Hayek had a genuine insight: individuals have limited cognitive capacity and diverse motives. Therefore, individuals cannot reliably assess whole societies, let alone predict the future of anything large-scale. However, says Hayek, within our own domains of experience and expertise, we can reasonably predict specific prices. After a tough spring, farmers will expect the price of wheat to rise.

Prices allow us to plan efficiently. Many people do not seek to maximize wealth but to accomplish something else, such as holding onto a valued job or retiring soon. Nevertheless, the result of all their private planning is a market that is–in certain respects–efficient.

However, markets also create opportunities to profit by correctly predicting the large-scale situation. In turn, such predictions require assessing the present. For example, to guess how the US economy will fare over the next four years, it’s necessary to evaluate Donald Trump as a leader. One can buy bonds and other securities partly on the basis of such predictions. In this way, an accurate evaluation of Trump could pay off financially.

But Hayek’s defense of markets would not encourage us to trust the aggregate results of such thinking. Just because many people trade securities, it does not follow that their overall understanding of the present or their predictions for the society as a whole are reliable.

On the contrary, each participant in a market who tries to predict how a whole economy or country will perform is subject to the same cognitive limitations that–according to Hayek–beset us as voters and policymakers.

Markets do respond intelligibly to news. Wall Street indices fall every time Trump announces tariffs and rise whenever he seems to back off. But these changes are not predictive. In fact, we can easily predict market shifts as soon as we know what Trump says. The market adds little new information.

It’s true that putting money on the line gives an individual a motivation to think rigorously and critically. But motivations do not solve cognitive limitations. The businessmen who confided in Rattner said that they didn’t like “woke stuff” under Biden. Such feelings should not directly influence their market behavior under Trump. Nevertheless, their hostility to “woke stuff” could affect their stock trades by influencing their moods or by leading them to consume news and information that is tilted in favor of Trump. As cognitively limited creatures, we must rely on limited sources and a priori models–also known as ideologies.

In recent months, CEOs reported rising confidence in the economy, while consumers’ confidence slipped. A closer look at consumer confidence reveals that it fell by 28 points among Democrats but rose by 32.8 points among Republicans between January and February. So we can compare three changing predictions: those of corporate bosses, Democrats as consumers, and Republicans as consumers. Why do the Democrats diverge from the CEOs and the average Republicans?

• The CEOs tend to have different values from the Democratic consumers. If everyone agreed that Trump’s tax policies will boost corporate profits but hurt the environment, CEOs would be more positive than representative Democrats.
• The CEOs have different information from Democratic consumers. They are awash in data about their own balance sheets, plus business-oriented news. Democratic consumers are seeing negative assessments of Trump.
• The CEO’s and the Democrats probably hold different mental models of such fundamental issues as the role of government and businesses in our society. Everyone holds such models, without which we cannot absorb new information.
• Partisan identity is working as a powerful heuristic. Americans are using the party of the incumbent president to predict the economy. This may be unwise, but human beings must use heuristics, and a party label does convey relevant information if you combine it with a model of the society.
• Some people act performatively. I would probably answer almost any survey question about Trump in a way that made him look bad, even if I didn’t completely believe the literal truth of my response. Some may even buy financial instruments to make a point–witness the popularity of Trump’s cryptocurrency.
• Finally, the information that people absorb may reflect political agendas. Rupert Murdoch, Jeff Bezos, and other media barons want to affect public opinion, although their impact is uneven because news consumers are sorted ideologically.

This is not a simple model, but it does have a simple core. It is methodologically individualist, presuming that the decision-makers are human beings rather than classes or other abstractions. Regardless of their interests and social positions, these individuals are cognitively constrained and not primarily concerned with assessing the whole society. When they do make general assessments and predictions, these decisions reflect their mental models (which, in turn, often reflect their social positions), limited information, and concrete issues that are salient for them at the time. As a result, markets respond intelligibly to widely reported breaking news but have little predictive value.

See also: The truth in Hayek; making our models explicit; social education as learning to improve models; how intuitions relate to reasons: a social approach; etc.