OPEC Definition: OPEC, the Organization of the Petroleum Exporting Countries, is an intergovernmental group of oil-producing nations that coordinates how much crude its members pump in order to influence global oil prices. It works by setting production targets, or quotas, at regular ministerial meetings, and because oil demand responds slowly to price, a cut of even 1–2% of world supply can move prices sharply.
What Is OPEC?
Five countries founded OPEC in Baghdad in September 1960: Iran, Iraq, Kuwait, Saudi Arabia and Venezuela. At the time, a handful of Western oil companies controlled production and set the prices paid to host governments. The founders wanted the opposite arrangement, with the countries that owned the oil deciding how much of it reached the market.
Membership has changed over the decades as countries joined, left or were suspended, but the Gulf producers have always been the core. Saudi Arabia matters most because it holds the largest spare capacity, output it can add or remove within weeks. That gives Riyadh the power to discipline the market in both directions. The organization has its headquarters in Vienna.
Since late 2016, OPEC has worked with a wider group of producers, including Russia, through an alliance known as OPEC+. Most modern headlines about “OPEC decisions” refer to this larger group. To understand why its meetings move markets, you need to see how a quota actually changes the price of a barrel.
How Does OPEC Work?
OPEC ministers meet on a set schedule, and more often when markets are volatile. They agree on a total production target for the group and divide it into quotas for each member. Countries then adjust how much they pump, and secondary sources such as tanker tracking and industry surveys check whether they comply.
The price effect comes from the shape of oil demand. In the short run, drivers, airlines and factories cannot quickly change how much fuel they use, so demand barely responds to price. Economists call this inelastic demand. When supply shrinks even slightly, buyers bid prices up until enough demand is squeezed out, and that can require a large price move.
Consider a market consuming 100 million barrels per day that is roughly in balance. OPEC+ announces a cut of 2 million barrels per day, 2% of world supply. If demand falls by only 0.2% for every 1% rise in price, the market needs roughly a 10% price increase to shed 2 million barrels of demand. A barrel at $80 would climb toward $88, before counting any response from other producers.
Those other producers are the limit on OPEC’s power. Higher prices encourage US shale drillers and others to pump more, which gradually refills the gap the cut created. Traders therefore price OPEC decisions through futures contracts stretching months ahead, where the expected response of rival supply shows up.
OPEC vs. OPEC+
| OPEC | OPEC+ | |
|---|---|---|
| Founded | 1960 | 2016 (Declaration of Cooperation) |
| Members | Oil exporters with formal membership, led by Saudi Arabia | OPEC members plus Russia, Kazakhstan, Mexico and other partners |
| Structure | Formal organization with a charter and secretariat | Looser alliance coordinated through joint meetings |
| Market weight | Large share of world crude output | A larger share of world crude output and most spare capacity |
Why Is OPEC Important for Traders?
Oil feeds into almost every other market, so OPEC decisions travel far beyond energy. Higher crude prices raise transport and production costs, lift inflation and can push central banks toward tighter policy. They also shift currencies: oil exporters such as Canada and Norway tend to see their currencies strengthen when crude rises, while large importers such as Japan and India feel the opposite pressure on their exchange rate.
The 1973 embargo shows how far that chain can reach. Arab members of the group halted exports to the United States and other countries that backed Israel in the Yom Kippur War, and crude prices roughly quadrupled within months. The shock fed the stagflation of the 1970s, when inflation and unemployment rose together.
OPEC’s power has clear limits, and the risk for traders is assuming the group can always defend a price. In November 2014 OPEC chose not to cut output in the face of booming US shale supply, and Brent fell from above $110 in mid-2014 to below $30 in early 2016. In March 2020 talks between Saudi Arabia and Russia collapsed just as the pandemic hit demand. Prices fell so far that the May WTI futures contract settled at about −$37 a barrel on 20 April 2020, even after OPEC+ agreed a record cut of 9.7 million barrels per day.
Compliance is a second weakness. Members earn more by pumping above their quota while others restrain output, and OPEC has no way to enforce the rules. Announced cuts therefore move prices on the day, but the market often discounts them until tanker data confirms that barrels have actually been withheld. Sudden shifts around meetings are one reason oil trades with higher volatility than most major asset classes.
Key Takeaways
- OPEC is a group of oil-exporting countries, founded in 1960, that coordinates production targets to influence the price of crude.
- Because short-term oil demand barely responds to price, a supply cut of 1–2% can lift prices by 10% or more.
- OPEC+ extends that coordination to Russia and other non-members, and most modern output decisions come from this wider alliance.
- OPEC decisions reach far beyond oil, feeding into inflation, interest-rate expectations and the currencies of exporting and importing countries.
- The group’s power is limited by rival producers, weak demand and members that exceed their quotas, as the price collapses of 2014–2016 and 2020 showed.
What is the difference between OPEC and OPEC+?
OPEC is the original organization of oil exporters founded in 1960. OPEC+ is a wider alliance formed in 2016 that adds non-members such as Russia, Kazakhstan and Mexico, which coordinate their output with OPEC through the same meetings.
Does OPEC set the price of oil?
No. OPEC sets production targets, and the price is then decided by trading in futures and physical markets. Supply decisions shift prices, but demand, inventories and non-OPEC production can outweigh them.
Why do OPEC members sometimes produce more than their quotas?
Each member earns more by selling extra barrels while others hold back, so quotas carry a built-in temptation to cheat. The organization has no power to fine members, which makes overproduction a recurring source of tension.
How does OPEC affect petrol prices?
Crude oil is the largest cost in refined fuels, so a production cut that lifts crude prices usually reaches pump prices within weeks. Taxes, refining margins and exchange rates explain why the effect differs from country to country.
