MERGEMERGE is a regionally disaggregated integrated-assessment model, whose development was supported by the Electric Power Research Institute. MERGE is based on Global 2200, a dynamic general equilibrium model with five world regions and a single consumer in each region who makes both savings and consumption decisions. A simple climate model represents atmospheric lifetimes of CO2, CH4, and N2O, which yield global change in radiative forcing, and equilibrium and realized global-average temperature change. Illustrative impact functions are defined separately for market and non-market components. Market impacts are modeled as a quadratic function of realized temperature change, calibrated to pass through a judgmental point estimate that is consistent with the estimate of Nordhaus. Non-market impacts are modeled as a worldwide public good, for which each region's willingness to pay to avoid a specified temperature change is an S-shaped function of regional income (Manne, Mendelsohn, and Richels 1993).
A reduced-form Excel-based version of MERGE, called MiniMERGE, has recently been developed by EPRI to permit testing of alternative inter-regional burden-sharing schemes in a simplified environment. MiniMERGE allows the user to choose one of two discount rates and to specify one of four policy objectives for global emissions: business-as-usual; stabilize emissions at 1990 levels; stabilize CO2 concentrations at 550 ppm; or optimize emissions to minimize the present value of damages. Then, region-specific costs can be calculated under a user-specified assumption of how fast the allocation of global emissions shifts to equal per-capita entitlements. (Manne and Richels 1995). Each of the above models is operational and available. For more information, contact the following:
Integrated Energy Systems Division
ATTN: Richard Richels
Electric Power Research Institute
P.O. Box 10412
3412 Hillview Avenue
Palo Alto, CA 94303
The next section is Lawrence Livermore National Laboratory.