Statistical properties of approval ratings for governments

We elucidate the statistical mechanical properties of the approval rating time series of several governments from the social dynamics of complex systems and sociophysics points of view. We find that the distribution of approval rating volatility shows exponential independently on nations. Introducing "volatility temperature" defined with the exponential distribution, it could be understood generally that high and low temperature nations correspond to parliamentary cabinet and presidential systems, respectively. We also find that approval rating time series of many governments shows self-affine fractality with negative or positive correlation. Approval rating time series is typical one of few negative correlation phenomena.