The annual discovery rates for the conventional oil/gas and coal categories are inverted U-shaped curves over time. That is, discoveries tend to increase annually to a point at which ultimate resource availability constrains them. This basic relationship is somewhat responsive to prices.
The computation of discovery rates in IFs is a two#stage process. First, the model determines world annual discovery rate (WRD). It utilizes an initial discovery rate (RDI) and an annual increment in discovery rate (RDINR), which is multiplied by the number of the time cycle. That term, representing the increasing tendency of discoveries, is modified by the change in average global energy price (WEP) times an elasticity of discovery (ELASDI).
The third characteristic of discovery rates, the tendency of ultimate resource availability to constrain them, enters the computation of discoveries (RD) in the second stage. Regionally specific discoveries are a portion of the world discoveries (WRD). The portion is the remaining undiscovered regional resources over the initial total of undiscovered resources globally (WUNRO). Remaining regional resources are initial ones (RESOR) times the exogenous resource multiplier (RESORM) minus cumulative production to date (CUMPR) and minus known reserves (RESER). In the initial time step, cumulative production is zero, so that initial global undiscovered resources is simply the sum across regions of resources minus reserves. The user has available also a rate of discovery multiplier (RDM) with which to adjust the process.
Knowing discoveries, it is possible to update reserves. One simply adds discoveries and subtracts annual production (ENP). In the first energy category, the equation subtracts only conventional oil production (ENPC).