TITLE:
Mathematical Neurolaw of Crime and Punishment: The q-Exponential Punishment Function
AUTHORS:
Taku Yokoyama, Taiki Takahashi
KEYWORDS:
Neurolaw; Neuroeconomics; Econophysics; Tsallis’ Statistics; Hyperbolic Punishment Function
JOURNAL NAME:
Applied Mathematics,
Vol.4 No.10,
September
29,
2013
ABSTRACT: Whether people tend to punish criminals in a socially-optimal manner (i.e., hyperbolic punishment) or not is unknown. By adopting mathematical models of probabilistic punishment behavior (i.e., exponential, hyperbolic, and q-exponential probability discounting model based on Tsallis thermodynamics and neuroeconomics, Takahashi, 2007, Physica A; Takahashi et al., 2012, Applied Mathematics), we examined 1) fitness of the models to behavioral data of uncertain punishment, and 2) deviation from the socially optimal hyperbolic punishment function. Our results demonstrated that, the q-exponential punishment function best fits the behavioral data, and people overweigh the severity of punishment at small punishing probabilities and underweigh the severity of punishment at large punishing probabilities. In other words, people tend to punish crimes too severely and mildly with high and low arrest rate (e.g., homicide vs. excess of speed limit), respectively. Implications for neuroeconomics and neurolaw of crime and punishment (Takahashi, 2012, NeuroEndocrinology Letters) are discussed.