Before revision:  Despite the obvious differences between "brainless" physical Brownian motions and complex financial Brownian motions resulting from the aggregated investments of anticipating agents, we show that ] the two systems can be described with the same mathematics after all.
After revision:  Despite the obvious differences between "brainless" physical Brownian motions and complex financial Brownian motions resulting from the aggregated investments of anticipating agents, we show that P.R. Krugman. The Quarterly Journal of Economics, 106(3):669-682, 1991] the two systems can be described with the same mathematics after all.