Before revision:  This effect described by Krugman's model is supported by non-parametric measurements of the conditional drift and volatility from the data. 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:  This effect described by Krugman's target zone model ] the two systems can be described with the same mathematics after all.