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

This study aims to answer why the quality of PET bottles collected from supermarkets and public waste drop-off stations waste were contrastingly high and poor, respectively. This study developed a new contingent valuation approach which requested only simple comparison of perceptive stimuli by questionnaire respondents. This approach subsequently valuated the stimuli, like unwillingness toward waste sorting, based on outsourcing market prices. Unwillingness toward required actions for PET bottle recycling were evaluated by conventional Willingness-to-Pay (WTP) method and the new method. There was good agreement between two methods for weak and moderate unwillingness. The easiest and hardest actions are cap removal (1.77 JPN yen) and disposal in supermarkets (57.9 JPN yen), respectively. On the other hand, the unwillingness toward disposal in the su-permarket was valuated three times larger than that of WTP method. This difference between WTP and the new methods might suggest that the new method valuated not only perceived but also unconscious unwillingness. Large non-recognizable unwillingness toward bringing PET bottles from home to a supermarket might serve like a social filter to allow only recycle-conscious persons to participate in PET bottle recycle against large unwill-ingness. It eventually results in PET bottle collection with constantly good quality. Social implementation of psychological barrier like strong unwillingness in waste collection system might be promising for efficient waste separation, called "separate recycling participation, not wastes" approach.