| 摘要: | 許多低度開發國家的「都市一般廢棄物(Municipal Solid Waste, MSW)管理措施」，不僅不符合社會現狀、更危害到大眾健康，並威脅到自然生態系統。在已開發國家或工業化國家廣泛施行的「垃圾按量付費」(Pay-As-You-Throw, PAYT)，是依據家戶垃圾量來收費，該制度設計可同時兼顧環境保護、增進大眾健康，並降低財政負擔，且能有效率地管理廢棄物。本研究將以位在貝里斯的San Ignacio/Santa Elena城市為例，透過成本效益分析探討低度開發國家實施「垃圾按量付費」之成效。本研究結果發現有67%的家庭同意隨垃圾袋計收費用；同時，該措施的施行可望降低50%的垃圾量。回歸分析結果顯示教育、收入、家戶人數、及家戶對目前措施的滿意度，皆與「願付費用(Willing to Pay, WTP)」呈現正相關。另外，條件評估法(Contingent Valuation Method, CVM)的結果顯示，在「垃圾按量付費計畫」中，民眾對一個垃圾袋的「願付費用」平均金額為US$0.68，比我們所估計一個垃圾袋的邊際社會成本為US$0.56還多了US$0.12。 成本評估分析結果顯示，目前處理都市一般廢棄物的成本每公噸約為US$41，或可換算成每一個垃圾袋約為US$0.42，而施行「垃圾按量付費」的措施，其處理廢棄物的成本每公噸約為US$56，或每一個垃圾袋約為US$0.56。效益分析的結果為每公噸US$139，或每一個垃圾袋需徵收US$1.39，效益的淨現值(Net Present Value, NPV)估計數為US$168,758，效益成本比率達1.4。敏感度分析顯示貼現率介於0.02% ~ 0.10%之間時會有正的淨現值。進一步分析得知，「垃圾按量付費」施行的效益應在介於50-100%區間時，將可得正的淨現值。綜上，本研究發現透過成本效益分析(Cost-Benefit Analysis, CBA)，可幫助開發中國家更為全面的評估該決策的可行性。「垃圾按量付費」這樣的一個經濟措施，提供我們一個可行的架構，並同時降低施行「都市一般廢棄物(MSW)」管理措施的對環境的負面衝擊。因此，在發現施行「垃圾按量付費」措施所帶來的效益大於成本的情況下，本研究建議San Ignacio應實施「垃圾按量付費」措施。The systems set up to manage the municipal solid waste in many lower developing countries are outdated and pose dangerous public health risks to the citizenry and threats to the ecosystem. Economic instruments, such as Pay-As-You-Throw (PAYT) programs, which charges households based on the amount of waste set out for collection, have been used extensively in developed and industrialized countries, as a tool to bridge the gap of environmental protection and improved public health whilst meeting the financial gap for effective solid waste management (SWM). This research sought to carry out an integrated costs-benefit analysis of a PAYT program in lower developing countries using San Ignacio, Belize as a case study. Results show that 67% of those households sampled are willing to pay (WTP) per bag of waste set out and that the program would result in 50% reductions in waste collected. Regression analysis showed that education, income, household size and households’ satisfaction with the reliability of current service were positively correlated with WTP. Results of the contingent valuation survey showed that mean WTP is US$0.68 per bag which is US$0.12 higher than the estimated marginal social costs of US$0.56 per bag for the PAYT program.Cost assessment shows that, currently, the cost of residential SWM is approximately US$41 per tonne or an approximate $0.42 per bag as compared to US$56 per tonne or some $0.56 per bag with the proposed PAYT program. Benefits, per tonne however, are estimated at US$139 or $1.39 per bag. Net present value (NPV) estimates shows NPV of benefits is US$168,758 with a benefit – cost ratio of 1.4. Sensitivity analysis shows that discount rate of 2%, 4%, 7% and 10% yields positive NPV. Further analysis indicates that should only 25% revenues of PAYT are collected, the program will realize external benefits as a result of waste reduction. It is concluded that the Cost-Benefit methodology provides an integrated approach to assessing streams of costs and benefits in helping decision making in developing countries. PAYT, as an economic instrument, provides a cooperative and stakeholder friendly framework for solving the problem of simultaneously decreasing the negative impacts of residential SWM on the environment while bridging the gap of lack of resources for effective and efficient MSW management. PAYT should be implemented in San Ignacio as the benefits outweigh the costs. |
