"The complexity of the oil pricing arrangements makes it difficult to
demonstrate convincingly that benchmark oil prices
fully reflect physical supply and
demand conditions rather than the actions of uninformed financial
speculators.
Nevertheless, movements over time
in the price differentials for the various benchmark crudes are broadly
consistent with
changes in demand and supply. The
Brent-WTI spread provides a good example of the influence of such
factors on oil price
differentials. Prior to
2011, Brent and WTI prices generally moved in tandem, with the spread
largely reflecting
the costs of transporting
Brent-referenced crude oils to the United States. In recent years,
however, increased volumes of
crude oil from North Dakota and
Canada have flowed into Cushing, leading to a build-up in inventories.
Most pipelines
flow from the rest of North America
into Cushing, making it difficult to move the extra crude oil out of
Cushing.
This has led to persistent
inventory bottlenecks, which have weighed heavily on the price of WTI
over the past
18 months, leading the Brent-WTI
spread to widen to US$10–30 per barrel. The recent widening of the
Brent-WTI spread is also likely to reflect concerns about declining
production volumes in the North Sea."
Eine Studie von Stephanie Dunn und James Holloway über den komplexen Ablauf der Rohölmärkte, die Preisbildung und den Spread der Benchmarks Brent & WTI. Erschienen im Quarter Bulletin der Reserve Bank of Australia, Sydney (September 2012).