&gt; it&#x27;d be a fool&#x27;s errand to treat models like this as having to say anything about real-world policy<p>Then what kind of models should have something to say about policy? Simulations tend to emulate the observed phenomena of economies much better than traditional systems-of-equations models.<p>&gt; There&#x27;s no way I can encode a dynamic disequilibrating market process in this<p>Have you tried? There are plenty of easy examples in complex systems literature. We could probably find a simple non-linear mechanism to add to Norvig&#x27;s model to make the equilibrium unstable. He&#x27;s already got a bit of randomness, so the two combined would create dynamic disequilibrium. One of my favorite additions would be the possibility of catastrophic loss. Check out what happens to the dynamics when a transaction periodically results in the loss of all assets involved.<p>&gt; Capital accumulation is far too dynamic a process to lead to rich-get-richer outcomes<p>That&#x27;s a strange sort of statement. Are you saying this rich-get-richer phenomenon is an illusion or that because we can observe some counter examples one shouldn&#x27;t make the rich-get-richer claim despite the general tendency? If the latter, that&#x27;s like saying the stock market doesn&#x27;t exhibit momentum because it sometimes changes direction.