A focal fuel for many countries especially in the developing world is oil. Focusing on fossil fuels, if international (world or regional) markets for fossil fuels were perfectly competitive with no dominant market shares for the largest market participants, fundamental fuel scarcity would be reflected in fuel prices. The supply side of these markets is fundamentally determined by the evolution of the aggregate volume exporters intend to offer under the given market conditions and supply flexibility, whilst on the demand side the evolution of the level as well as the flexibility of demand are the fundamental factors.