柘植 隆宏

Cigarette butts (CBs) are the world’s most littered item and significantly contribute to environmental pollution. A deposit-refund system (DRS) has been proposed to reduce CB littering, but its effective design remains underexplored. This study addressed this gap by investigating smokers’ perceptions and preferences in hypothetical DRS scenarios for CBs. We conducted a discrete choice experiment in Japan (n = 1,865) and Indonesia (n = 2,000). Respondents were divided into treatment and control groups, with the treatment group receiving information on CB environmental impact aligned with the WHO’s campaign. Our results revealed that a DRS for CBs was preferred to the status quo, with higher preferences in Indonesia (90.33%) than in Japan (63.92%). The information treatment further increased DRS preferences (Indonesia: 91.82%; Japan: 69.83%) and willingness to endure cost to support DRS operations. Cost simulations showed participation probabilities remained above 55% with a cost of up to 5% of a cigarette’s price in Japan, and above 80% with a cost of up to 10% in Indonesia. Our findings underscore the importance of environmental information in DRS adoption. Both countries preferred a producer-managed system to a government-managed one, highlighting an opportunity for tobacco producers to fulfill extended producer responsibility through a DRS. Furthermore, DRS design should be country-specific. Notably, Japanese respondents’ familiarity with heat-not-burn cigarettes influenced their preference for a tailored DRS to those products, whereas Indonesian respondents preferred a DRS for CBs. Japanese respondents also emphasized accessibility more than their Indonesian counterparts.

<p>Wildlife overexploitation is a significant challenge in biodiversity conservation. Regulation can enforce consumer behaviour change to be biodiversity-friendly but also cause unintended negative impacts. A quantitative investigation of consumer preference for alternative goods is needed before the regulation intervention. This study focused on a case of Japanese eels that are threatened with extinction due to commercial fishery and overfishing and clarified potential alternative choices after the market regulations. This study employed a best–worst scaling technique. Our analysis specifies the two consumer groups; approximately 30% of consumers (“Potential Illegal” group) may select illegal eel consumption as their second-best preference. The Potential Illegal group tends to contain males, younger, and people who eat eels once or more annually, in comparison to the other group. Our findings can contribute to setting effective regulations as useful information about potential consumer choice changes.</p>

Summary Message framing contributes to an increase in public support for invasive species management. However, little is known about people’s preferences for the multiple objectives of management within different contexts relating to the challenges and benefits of invasive species management. We examine Japanese citizens’ preferences for the goals of free-roaming unowned cat (Felis catus) management in three contextual frames by applying experimentally controlled information and the best–worst scaling technique. Our results indicate that the ecological frame highlighting the ecological impacts of free-roaming unowned cats on native ecosystems significantly increases Japanese citizens’ concern about cat predation, although the frame did not change the preference ranking of goals. There are differences in the effects of message framing depending on cat ownership. The best–worst scaling technique shows that Japanese citizens prefer to maintain a sanitary environment, followed by the prevention of zoonotic diseases. Although the ranking of sanitary environmental management does not depend on cat ownership, the ranking of the other goals differs depending on cat ownership. The findings highlight the importance of strategic message framing and its prioritization in encouraging public support for invasive species management.

<p>生物多様性条約を中心として，長年にわたり国際的議論の的となってきた遺伝資源アクセスと利益配分（ABS）は，名古屋議定書の採択・発効や日本の国内措置「ABS指針」の施行により，改めてABSの意義や具体的な実現策が問われる段階に入っている．今後の国際的および国内的なABS政策への社会科学的基礎の提供に向け，これまで日本で先行してきた法学研究の動向を踏まえながら，「遺伝資源利用の経済理論」「遺伝資源の経済価値評価」「企業の遺伝資源利用行動」の3つの側面から経済学の先行研究の検討に基づいて今後の研究課題を展望する．</p>