都市垃圾清運方式對資源回收量影響之時間序列分析：以垃圾不落地措施為例

Time Series Analysis of the Effects of Refuse Collection Practice on the Outcomes of Recycling in Cities: An Example of the 'Keep Trash off the Ground' Measure

近幾年來在環保機關各種資源回收政策實施下，台灣地區資源回收成效已出現相當顯著的提升，這些主要的政策包括垃圾不落地、四合一資源回收制度、垃圾費隨袋徵收、強制垃圾分類等，然而造成全面而關鍵性顯著影響的可能是哪一政策，是非常值得探究的重要問題。由於垃圾不落地措施使民眾得以更方便地參與資源回收，因此本研究以回溯性的形式，分析了台灣三大都市過去十年歷月的資源回收量數據，採用時間序列介入模式來分析垃圾不落地措施對這些都市資源回收量影響的程度，強制垃圾分類、垃圾費隨袋徵收的影響也一併分析。結果顯示屬於垃圾清運措施變革的垃圾不落地，對這些都市的資源回收量的影響程度是一致且顯著的，很可能是今日台灣資源回收成果得以提升的主要因素。此結果凸顯了廢棄物管理甚或是試圖改變民眾環境行為的環境政策中，對民眾的教育宣導固然是必須的，但能符合實際情況、便利民眾配合的執行技術可能是民眾環境行為順利展現、整個政策得以成功的重要關鍵。

Due to major recycling policies implemented by environmental agencies in recent years, there have been significant improvements in recycling in Taiwan. These policies include so-called the ”Keep Trash off the Ground” (KTOG) measure, the ”Four-in-One Recycling Plan,” the ”per-bag trash collection fee” and mandatory garbage sorting. Determining which of these policies has had the greatest impact on recycling is worthy of in-depth investigation. The KTOG measure increased the convenience for people participating in recycling. This retrospective study examined the monthly data for quantity of recyclables over the past decade in Taipei, Taichung, and Kaohsiung, Taiwan's three major cities. The time-series intervention model was applied to determine the extent to which the KTOG measure affected the amounts of recyclables generated by these three cities. The effects of mandatory garbage sorting and the ”per-bag trash collection fee” were also examined. Analytical results indicated that the KTOG measure, which is essentially a change in refuse collection practice, has consistent and significant effects on the amounts of recyclables generated in the three cities. In urban waste management, the techniques tailored to actual settings facilitating the cooperation of residents may central to engendering the behaviors that make the policy successful.