I don't think that a complete solution is necessary.  The one thing I remember from college is that complex equations are most easily solved at boundaries.  In the case of Raleigh's wave equation for acoustics, which involves the interrelations of pressure variations and the variations of air movement or "volume velocity," this is typically done at a rigid boundary or wall at which volume velocity is zero.  An amazing number of practical measurements and useful techniques come out of this simplifying assumption.

A similar approach might prove fruitful in economic modeling.  What I had in mind was a system of interacting agents in which the A.I. agents automated certain aspects of their response with other agents but in which the controller for each agent could intervene on whatever basis seemed appropriate to that controller.  The goal would be to define sub-sets of assumptions that would tend towards stability under a wide range of perturbations, including the desire of individual agent controllers, or players, to win.

In this fashion it may be possible to empirically move from very crude and simple systems to increasingly complex systems while maintaining stability.  In such a game I would at best be a mediocre player.  

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."