摘要:This paper extends Ito et al. (2010) to reveal whether altruism is an underlying motive of the behavioral thresholds. We also investigate the influence of environmental concern as one of the underlying motives of them. Applying contingent valuation (CV) methods, we conducted a stated preference survey to study people's cooperative behavior in the donation to Green Power Fund (GPF). We use latent class approach in order to examine the underlying motives of the thresholds. The results show that the participation rate in the donation to the GPF, which completely cancels out the amount of CO2 emission from a household's electricity consumption, is estimated as 59.24% at the psychosocial equilibrium when the suggested donation amount is 500 yen. We found that for a latent class with higher altruism and environmental concern there is a statistically significant impact of the equilibrium participation rate through behavioral thresholds.