One of the most famous cartels of the past 50 years is OPEC, the Organization of Petroleum Exporting Countries. The members of OPEC are countries rather than individual businesses. Oil Ministers from each of the countries meet regularly to establish how much each oil each country will produce each month (the amount each country agrees to produce is called its quota). Saudi Arabia is the largest oil-producing country in OPEC. Why does Saudi Arabia usually produce less than its quota each month?