All these models share a distinctive feature: they are formulated as a system of differential equations in percentage change form; however, this is not required by GEMPACK.
A characteristic feature of CGE models is that an initial solution for the model can be readily constructed from a table of transaction values (such as an input-output table or a social accounting matrix) that satisfies certain basic accounting restrictions.
GEMPACK builds on this feature by formulating the CGE model as an initial value problem which is solved using standard techniques.
These all require solution of a large system of linear equations; accomplished by sparse matrix techniques.
The underlying numerical approach is complemented by several GUI programs that: ease viewing of large multidimensional arrays often found in CGE databases; manage complex (e.g., multi-period) simulations; and allow interactive exploration and explanation of simulation results.