From the Document: "Since the beginning of the oil industry, there have been multiple periods when a supply manager has influenced production and price levels. Generally, a supply manager has the capacity to adjust production rapidly in order to respond to changing market conditions. The limited ability of oil production and consumption to adjust in the short term, coupled with long development cycles for most oil production assets, a desire for price stability, and volatile price movements when the market is imbalanced by as little as 1% to 2% are some stated justifications for supply management. In the past, the Standard Oil Company, the Texas Railroad Commission, and international oil companies have functioned as supply managers. Today, the 14-member Organization of the Petroleum Exporting Countries (OPEC)--representing approximately 40% of the nearly 100 million barrels per day (mbpd) of world liquid fuels supply (see Figure 1)--makes crude oil production decisions that can affect global petroleum prices."
CRS In Focus, IF11186
Congressional Research Service: https://crsreports.congress.gov/