The worldwide trend of rising economic inequality applies not only to individuals. Consider what’s happening among corporations.

Companies in the top one-fifth of profitability earn, in aggregate, about 70 times more economic profit (accounting profit less cost of capital) than those in the middle three-fifths combined, according to McKinsey’s database of 3,000 large, publicly listed, nonfinancial U.S. firms.

Moreover, the economic profit of companies that were in the top fifth in 1997 (at the start of the dataset) grew by close to 50% over the subsequent 15 years, so that the gap between the most and least profitable firms in the sample increased over time.

Sound familiar? Even in the corporate world, the rich are getting richer.

As for whether this is a new phenomenon, consider McKinsey’s dataset, stretching back to the 1960s, on 5,000 U.S. companies’ return on invested capital (ROIC), and compare it with economy-wide ROIC estimates constructed by Deloitte. The comparison is imprecise, of course, but nevertheless suggestive.

Economywide ROIC has trended downward since the 1980s, falling from above 6% in the mid-1960s to 5% in 1980, then to 3% in 1990, and to only a bit more than 1% by 2010. Deloitte attributes this fall in part to rising competitive intensity, as a result of new technologies and lower entry barriers.

But this phenomenon of rising competitive intensity does not, evidently, apply to all firms. An increasing number of U.S. companies have enjoyed supernormal rates of return. In 1960, only a tiny proportion of major American firms earned an ROIC of 50% or more. The proportion rose slowly and relatively steadily, reaching 5% by the mid-1990s. It then leapt suddenly to 14% by the 2005–2007 period.

So although you might expect that in a hypercompetitive environment, ambitious companies would constantly wrest market share from the leading firms, the reality is quite the opposite.

It appears that some firms have recently become rather insulated from competition and that the performance of these corporate “haves” is diverging from that of the large majority of “have-nots.”

So when billionaire Peter Thiel writes that “there is an enormous difference between perfect competition and monopoly, and most businesses are much closer to one extreme than we commonly realize,” he is onto something.

What are the underlying drivers of this trend? There are many. But the one I would point to first is the rising popularity and growing applicability of patents. McKinsey notes that since the 1960s, the industries that have sustained the highest average returns are those that “rely on sustainable competitive advantages such as patents and brands.”

And patenting activity has recently exploded. The number of patents filed in the U.S. doubled over the 30 years from 1960. The figure then grew by about 3.5 times over the subsequent 20 years. This acceleration was in part driven by the extension of patent law to apply to software in the 1980s, and then by its further extension to business processes in 1998.

Is this a bad thing? To be sure, corporations are not people (except in the legal sense) and don’t feel jealousy or vote for radical wealth redistribution when stuck at the bottom of the ladder. Senior executives in even chronically low-performing sectors (such as airlines) can be successful and well-remunerated. And even if some firms have been stuck at the top of supposedly dynamic industries (Microsoft, Apple) for a rather long time, others have used innovation to rise rapidly (Facebook, Twitter).

But I wonder whether some of the chronic underinvestment we have experienced since the global financial crisis isn’t related to the phenomenon of escalating corporate inequality. Overall corporate profits are at record highs of roughly 21% of GDP. Companies are using this money for share buybacks, or putting it in the bank, running high (and rising) cash balances of close to 15% of GDP. So the problem isn’t a lack of funds.

Which suggests a worrying alternative explanation. It’s the companies at the top of the food chain that have historically tended to invest the most, according to McKinsey. And if the past distribution of economic profits is any guide, these are the companies earning the overwhelming majority of the record profits of today. If these companies are facing less and less effective competition, how much do they need to invest to maintain their dominance?

The data on cash balances suggests an answer: not very much.

This underinvestment has a real cost to U.S. economic performance. Results of a scenario using the Oxford Economics global macroeconomic model suggest that if corporations threw the money they are keeping in the bank into capital investment instead, U.S. GDP growth could hit nearly 5% in 2016.

But as long as these companies remain above the competitive fray, it’s hard to imagine such an investment-led boom happening.