Comment by semiquaver

  > It usually results in a spiral that is negatively self reinforcing

In the case of oil, suppliers would stop pumping when it was no longer economically viable to do so, contracting supply and thus raising the price until it reached equilibrium. The same should be true of other goods. Why do you think that decreasing prices tends to create a downward spiral?

The price signal cannot function if it can only move in one direction.