“OPEC is being caught in a pincer movement of technology and policy that will, over time, erode oil use,” said Bill Farren-Price, chief executive of Petroleum Policy Intelligence, an advisory firm for hedge funds and other investors. “This meeting is more about forestalling an oil price collapse than driving prices higher.”

Here are some factors muting the impact of the cuts to output.

The Shale Boom

Oil prices that topped $100 a barrel as recently as 2014 may have helped plant the seeds that are now weakening OPEC.

Back then, companies in the United States took advantage of the high prices, learning to produce huge quantities of oil from shale rock in a process called hydraulic fracturing, or fracking. The technique, which involves extracting energy by drilling long horizontal wells, then loosening oil from the rock, has transformed the United States into what is known as a swing producer, able to adjust production rapidly to match changes in the market.

But fracking has required substantial investment. When oil prices plummeted in 2015 and 2016, output from shale in the United States fell about 900,000 barrels a day, equivalent to almost 1 percent of the global supply.