AMERICA is a grumpy and confused place. For an overarching explanation of what has gone wrong, a decline in trust is a good place to start. Trust can be defined as the expectation that other people, or organisations, will act in ways that are fair to you. In the White House and beyond there is precious little of it about. People increasingly view institutions as corrupt, strangers as suspicious, rivals as illegitimate and facts as negotiable.

The share of Americans who say “most people can be trusted” fell from 44% in 1976 to 32% in 2016, according to a survey from the University of Chicago. In a new book, “The Retreat of Western Liberalism”, Edward Luce, a commentator for the Financial Times in Washington, argues that distrust will contribute to America’s decline and eventually, even, to autocracy. Lack of faith is chewed over in boardrooms, too. In his latest letter to shareholders, Jamie Dimon, JPMorgan Chase’s boss, describes trust as America’s “secret sauce” and worries that the bottle is running dry.

The tricky bit is reconciling this distrust with the rosy business outlook. The S&P 500 index is near an all-time high, even though many economists say that distrust is toxic for prosperity because transactions become dearer and riskier. An OECD study of 30 economies shows that those with low levels of trust, such as Turkey and Mexico, are far poorer. Three scholars, Luigi Guiso, Paola Sapienza and Luigi Zingales, have shown that pairs of countries (such as Britain and France) whose populations say they distrust each other, have less bilateral trade and investment.

America’s mistrust outbreak can be split into two parts: what consumers think, and what firms think. The share of folk who have “little or no confidence” in big business has risen from 26% in 1976 to 39% in June, according to Gallup. For banks it has risen from 10% in 1979 to 28% today. Over decades big firms have broken implicit promises to their employees, such as providing a job for life and paying generous pensions. That has probably soured the public’s view. And the financial crisis of 2007-08 blew a giant hole in the reputation of big business and finance.

Yet despite their customers’ distaste, big firms mint huge profits. One explanation is declining competition over the past 20 years. If markets are working, firms that are perceived to behave badly lose market share. In concentrated industries this discipline is lacking. Two recent scandals in oligopolistic bits of the economy illustrate the point. Wells Fargo, a bank, created millions of fake accounts, yet in the three months to June its year-on-year profits rose by 5%. In April a United Airlines passenger was assaulted, causing an outcry. Its underlying profits later rose by 5%, too. In such industries Americans are inured to mistreatment.

Trust between firms, and between firms and investors, is more resilient, but there is evidence of greater wariness. Banks charge corporate borrowers a spread of 2.6 percentage points above the federal-funds rate, compared with 2.0 points in the 20 years before the crisis. The equity-risk premium, or the annual excess return that investors demand to hold shares rather than bonds, is 5.03 points, against a pre-crisis average of 3.45 points, notes Aswath Damodaran of the Stern School of Business at NYU.

The median firm in the S&P 500 holds 62 cents of cash on its balance-sheet per dollar of gross operating profit, up from 45 cents in 2006 (this yardstick excludes America’s giant technology companies, which hoard money). In a sign that more corporate deals end in tears, litigation costs are rising. The revenues of legal firms rose by 103% in 1997-2012, according to the Census Bureau, more quickly than nominal GDP growth, of 85%. And spending on corporate lobbying, a signal that firms think politicians are corruptible, has risen faster than GDP, too.

In the long term it is possible that firms could become as mistrustful as consumers. Though individual companies can gain from cronyism, overall confidence will fall if there is sustained political meddling in the courts and regulatory system. And companies as well as people can be trapped into doing business with monopolies that are inept or shifty. In 2016 Facebook said that for the past two years it had overstated how long its users watched videos for, but advertisers have little choice but to stick with the social-media firm. Its profits rose by 71% in the latest quarter.

If the bleak predictions of observers such as Mr Luce come true, how might America Inc adjust? One guide is the work of Ronald Coase, an economist who theorised that the boundary of a firm is set according to whether an activity is best done in-house or can be outsourced to the market. If counterparties are less reliable, and contracts expensive to enforce, firms will become “vertically integrated”, bringing their supply chain in-house.

If there is deeper decay of America’s legal system and greater political corruption, then firms would go further and spread “horizontally” too, expanding into new industries where their political contacts, and access to favours and capital can be used. This is how business works in much of the emerging world.

Gotta have faith

America is nowhere near such an outcome, at least not yet. Still, a concerted effort to shore up trust between consumers and firms, and between firms, would be healthy. If you subscribe to Silicon Valley’s Utopianism, technology can fill the gap, manufacturing mutual faith where none existed before. Uber’s system of scoring drivers and passengers allows strangers to have confidence in each other. E-commerce sites such as eBay and Alibaba work by creating networks of trust between merchants and customers.

In the end, however, government has a vital role. By enforcing competition rules, it can ensure that poor conduct is punished. And by observing the independence of courts and regulators, it can demonstrate that contracts are sacred and that firms operate on a level playing-field. Suspicion is not about to bring American capitalism to its knees. But the country’s vast stock of trust, built up over a century or more, is being depleted quickly.