A case study of unwillingness toward PET bottle recycling behaviors - a new contingent valuation approach which requests only simple comparison of perceptive stimuli

•Unwillingness toward eight actions for PET bottle recycling process was valuated.•The new method can valuate unwillingness including unconscious part.•Moderate unwillingness to disposal rule understanding explains failed separation.•Strong unwillingness realizes collection of only clean PET bottles in supermarkets.•Social implementation of psychological barrier helps less waste contamination.