M.A. Adelman and G.C. Watkins, November 2003
A time series is estimated of in-ground prices - as distinct from wellhead prices – of US oil and natural gas reserves for the period 1982-2002, using market purchase and sale transaction information. The prices are a measure of the unit investment cost (long-run marginal cost) of creating new oil and gas reserves. The data are also used to examine the impact of reserves status (producing or not), the rate of production (R/P ratios) and of wellhead prices on reserve prices, and to reveal oil and natural gas price expectations embedded in reserve prices. Noticeable differences are disclosed between oil price expectations (ambiguous) and natural gas (positive). Estimates are made of current market values of US oil and gas reserves.
Over the 21 year time span studied the trend in oil reserve prices is zero to mildly negative, that in natural gas is zero to mildly positive. All of these results -- the reserve prices themselves, their trends, and estimates of one year returns on holding reserve assets-- are incompatible with Hotelling doctrines. All these estimates refute the assumption of a fixed stock of hydrocarbons whose incessant decrease by production makes the still unproduced remainder constantly more valuable. The results are compatible with a process whereby investment adds to reserves even as production depletes them.