In March 2000, OPEC decided to stabilise oil prices within a range of 22-28 US-Dollar/barrel of crude oil. Such an oil-price-level is far beyond the short and long run marginal costs of oil production, beyond even that in regions with particularly high costs. Nevertheless, OPEC may achieve its goal if world demand for oil increases substantially in the future and oil resources outside the OPEC are not big enough to accordingly increase production. In this case OPEC, which controls about 78% of world oil reserves, has to supply a large share of that demand increase. If we assume OPEC will behave as a partial monopolist on the oil market, which takes into consideration the reaction of the other producers to its own sales strategy, it can reach its price target. Lower prices before 2020 are probable only if the OPEC cartel breaks up. Higher prices are possible if production outside OPEC is inelastic as assumed by some geologists, but they would probably stimulate the production of unconventional oil based on oil sand or coal. Crude oil prices above 30 US-Dollar/barrel are therefore probably not sustainable for a long period. (C) 2003 Elsevier Ltd. All rights reserved.