Greedy corporates are increasing prices--that stimulates inflation.

The prices of oil, transportation, food ingredients and other raw materials have fallen in recent months as the shocks stemming from the pandemic and the war in Ukraine have faded. Yet many big businesses have continued raising prices at a rapid clip.

Some of the world’s biggest companies have said they do not plan to change course and will continue increasing prices or keep them at elevated levels for the foreseeable future.

That strategy has cushioned corporate profits. And it could keep inflation robust, contributing to the very pressures used to justify surging prices.

As a result, some economists warn, policymakers at the Federal Reserve may feel compelled to keep raising interest rates, or at least not lower them, increasing the likelihood and severity of an economic downturn.

“Companies are not just maintaining margins, not just passing on cost increases, they have used it as a cover to expand margins,” said Albert Edwards, a global strategist at Société Générale, referring to profit margins, a measure of how much businesses earn from every dollar of sales.

PepsiCo has become a prime example of how large corporations have countered increased costs, and then some.

Hugh Johnston, the company’s chief financial officer, said in February that PepsiCo had raised its prices by enough to buffer further cost pressures in 2023. At the end of April, the company reported that it had raised the average price across its snacks and beverages by 16 percent in the first three months of the year. That added to a similar price increase in the fourth quarter of 2022 and increased its profit margin.

“I don’t think our margins are going to deteriorate at all,” Mr. Johnston said in a recent interview with Bloomberg TV. “In fact, what we’ve said for the year is we’ll be at least even with 2022, and may in fact increase margins during the course of the year.”

The bags of Doritos, cartons of Tropicana orange juice and bottles of Gatorade sold by PepsiCo are now substantially pricier. Customers have grumbled, but they have largely kept buying. Shareholders have cheered. PepsiCo declined to comment.

What is inflation? Inflation is a loss of purchasing power over time, meaning your dollar will not go as far tomorrow as it did today. It is typically expressed as the annual change in prices for everyday goods and services such as food, furniture, apparel, transportation and toys.

What causes inflation? It can be the result of rising consumer demand. But inflation can also rise and fall based on developments that have little to do with economic conditions, such as limited oil production and supply chain problems.

Is inflation bad? It depends on the circumstances. Fast price increases spell trouble, but moderate price gains can lead to higher wages and job growth.

How does inflation affect the poor? Inflation can be especially hard to shoulder for poor households because they spend a bigger chunk of their budgets on necessities like food, housing and gas.

Can inflation affect the stock market? Rapid inflation typically spells trouble for stocks. Financial assets in general have historically fared badly during inflation booms, while tangible assets like houses have held their value better.

Other companies that sell consumer goods have also done well while continuing to raise prices.

The average company in the S&P 500 stock index increased its net profit margin from the end of last year, according to FactSet, a data and research firm, countering the expectations of Wall Street analysts that profit margins would decline slightly. And while margins are below their peak in 2021, analysts forecast that they will keep expanding in the second half of the year.

For much of the past two years, most companies “had a perfectly good excuse to go ahead and raise prices,” said Samuel Rines, an economist and the managing director of Corbu, a research firm that serves hedge funds and other investors. “Everybody knew that the war in Ukraine was inflationary, that grain prices were going up, blah, blah, blah. And they just took advantage of that.”

But those go-to rationales for elevating prices, he added, are now receding.

The Producer Price Index, which measures the prices that businesses pay for goods and services before they are sold to consumers, reached a high of 11.7 percent last spring. That rate plunged to 2.3 percent for the 12 months through April.

The Consumer Price Index, which tracks the prices of household expenditures on everything from eggs to rent, has also been falling, but at a much slower rate. In April, it dropped to 4.93 percent, from a high of 9.06 percent in June 2022. The price of carbonated drinks rose nearly 12 percent in April from 12 months earlier.

“Inflation is going to stay much higher than it needs to be, because companies are being greedy,” Mr. Edwards of Société Générale said.