Criticality and punctuated equilibrium in a spin system model of a financial market

Recent works on self-organised criticality (SOC) in pulse coupled relaxation oscillators have shown SOC to be related to frustrated attempts of the system to synchronise. Criticality has also been connected to punctuated equilibrium behaviour. We describe a model which shows a non-equilibrium phase transition and seems to link these two ideas. Near the transition, punctuated equilibrium behaviour is seen, with avalanches occurring on all scales. This scaling is described by an exponent very near 1.