Other factors that have an impact.
I would add to your list the regulatory mandates which inflate the price of refined gasoline. The requirement to have different blends in different localities raises the price significantly. The mandate to blend ethanol has an adverse impact for the consumer as well.
Speculation, currently, plays a major role in keeping the price of oil high. The western benchmarks, West Texas Intermediate and Brent Sea Intermediate serve as a major benchmark for the all the other grades. Production of each is only a very small percentage of global production each day and they are delivered only locally for refining. With total production of Brent and WTI only a few billion dollars worth a day. It is quite easy for a small number of traders to bid up the long contracts for a sustained period. If these benchmarks are inflated then every other grade that is priced off the benchmarks will be inflated as well. There is no other way to explain the persistently high prices in the face of falling oil demand and ever increasing production. Eventually, the long positions in Brent and WTI will be unsustainable and prices will collapse.
