台灣主要國家公園之效益評估－－納入時間成本之需求體系旅行成本法

Benefit Evaluation of National Parks in Taiwan: A Demand System Approach Using Travel Cost Method and Value of Time

本文的目的是考慮消費者行為理論，由旅行成本函數之設定出發，建構個別旅遊者對墾丁、玉山、陽明山、太魯閣、雪霸五個國家公園的完整旅行需求體系模型，並以補償變量估算出五個國家公園的遊憩效益。進而比較以需求體系估算出的遊憩效益，與以個別需求函數估算出之國家公園的遊憩效益，作為效益衡量上考慮替代關係或未考慮替代關係結果差異之檢視。而實證所使用的為一份墾丁國家公園資源經濟效益評估之問卷中，得以提供作為本研究驗證前述概念用的資料。結果顯示，以職業別的工資率計算旅行時間的價格，作為時間機會成本的依據，而依受訪者所居住區位至國家公園的區域變數，確實說明了距離遠近對於旅行次數的影響，此乃說明了遊憩者居住地區與遊憩地點距離對遊憩次數之關係，更顯示出在多個旅行地點間亦因距離遠近的影響而造成替代互補的關係。又模型評估後所得到效益值顯示，本島五個國家公園若消失或關閉時，欲使消費者達到原國家公園存在情況的效用水準所需的每年每人補償效益值，介於897.87～2,674.69 元之間，其中以墾丁國家公園的效益值最高，而玉山國家公園與雪霸國家公園的效益值則相對較低。最後，由本需求體系模型估算所得的整體效益結果可知，考慮替代地點間的影響可取得合理且正確的效益評估值，以旅行需求體系求算出之五座國家公園遊憩效益總和為9,083.63 元，遠小於個別估計出的五座國家公園遊憩效益總和的47,353.37 元，此一結果說明了忽略替代地點所造成的效益偏誤非常明顯。

The purpose of this study is to construct a complete demand systemfrom the function of travel cost base upon the consumer behavior forKenting,Yushan, Yangmingshan, Taroko, and Sheipa national parks.The total benefit is then estimated through compensating variation forthese five national parks accordingly. Furthermore, the total benefit ismade to compare to the one which without accounting for the substitutionand complementarity among the sites.The results show that the value of time varies by occupational wagerate does indicate the influence of the numbers of travel times that therespondent lives to a specific national park. This further demonstratesthe substitution and complementarity among sites while traveling amongmultiple sites. The compensating variation for these five national parksranges between 897.87 to 2,674.69 NT dollars. Among these, theKenting national park has the highest benefit and those for Yushannational park and Sheipa national parks are relatively low.Finally, the total benefit for these five national parks while accountingfor the substitution and complementarity is 9,083.63 NT dollars. Thisvalue is relatively lower than the values when each park is estimatedindividually without taking into account the relationship among the sites.