The invisible hand fucks up:

Politics and human nature create bubbles of instability in pricing, causing serious harm and specious profits. Worldwide the rice price spiked one summer in the ninties. Boring but important to think about.

It just needs damping!  What if we had big stockpiles of key materials, oil and grain and copper, and these had programmed demand elasticity? They'd be thereby automatically rigged to foil speculative trading. (#320)