Here is one for the theorists amongst you - a longer and deliciously academic paper available on request. But for now just enjoy the sense of complete upset that could be caused to a neoclassical economist by the thought that, not only is there supply and demand model (see the figure) ridiculously simplistic, but both lines might actually be oriented in the opposite direction from those conventionally illustrated.
Such is the hypothesis of the German-New Zealand economist Stefan Arne Kesting, who argues that, not only might the directions of the two curves be reversed, but it might actually be possible to posit that an equilibrium is reached.
Conventionally (see the diagram) the supply curve is illustrated as upward sloping, since as the price of a good increases the producer is willing to supply more. However, Kesting points out that, 'Based on arguments of economies of scale and increasing returns by Alfred Marshall. . . marginal and average costs of production and prices are shown to decrease in some instances when output is extended.' This might suggest a supply curve that slopes downwards for a certain range of prices.
In the case of the demand curve, Kesting argues that Veblen's ideas about conspicuous consumption might cause this to be upward sloping. The conventionally downward sloping curve is based on the assumption that as goods increase in price people buy less of them. But if those goods are status goods, the higher price might increase demand (superior branded clothes might be an example).
Kesting argues that the two curves might again meet at an equilibrium point, although each is the mirror image of that suggested by orthodox economic theory.
The easy way in which the most basic apparently scientific formulation of neoclassical economy theory can be turned on its head in this way indicates clearly the vulnerability of the whole house of cards by which our complex global economy is justified.