距離與願付價值關係再檢視--受限分量迴歸模型之應用

Abstract

過去文獻隱含距離與願付價值之間呈現唯一的負向關係，也就是距離衰退現象。而本文從保護區之劃設而受犧牲的利害關係人角度觀察，重新檢視距離與願付價值之間的關係。應用受限分量迴歸模型，不同分位數的迴歸估計式以更精確的觀察距離在各分量願付價值下的影響，並以墾丁國家公園、彰化海岸濕地與黑面琵鷺保護區分別為研究地區。其中，墾丁國家公園由於樣本多為使用者所組成故代表使用者樣本，而彰化海岸濕地與黑面琵鷺保護區樣本多由非使用者所組成故代表非使用者樣本。 根據分析結果顯示，使用者與非使用者樣本所代表的不同自然資源財貨之距離確實對願付價值有顯著的影響，距離隨著願付價值的增加而上升。其中，離自然資源保護區越近的當地居民越有可能因為保護區的設立受到法規限制進而被迫改變原本的生活型態或禁止開發活動。反之，離自然資源保護區較遠的一般民眾在無法規限制的情況下，反而會因為保護區自然資源受到良好的維護進而產生非使用價值與存在價值。又從距離彈性值可以發現在不同自然資源財貨下，距離對當地居民的彈性大於一般民眾，亦即距離變動對當地居民願付價值有最大的影響效果。至於墾丁國家公園、彰化海岸濕地與黑面琵鷺保護區的自然資源總價值分別為94億元、82億元與51億元，故使用者在距離影響下的資源總價值高於非使用者。

Most studies in the literature implied relationship between distance and willingness to pay is negative, so-called distance decay phenomenon. The purposes of this paper will view an issue from stakeholder perspective and revisit the relationship between distance and willingness to pay. Therefore, conduct a censored quantile regression model for three suitable sets of data to portray the relationship between distance and willingness to pay. One set of data is mainly concerning the users of natural resources as Kenting National Park. As such this set of data can be a representation of user samples. And the other two sets of data are composed majorly by the nonusers of natural resources, i.e. Black -faced Spoonbill Protected Area and Changhua Coast Wetland. These data can thus be a representation of nonuser samples. The estimate results show that distance and willingness to pay for either user or nonuser samples does have significant effects. While according to the limitation of natural resources for those who reside close to the resource sites, distance and willingness to pay reveals one dimensional positive relation. The closer to the resource site will lead to lower willingness to pay. Residents who live in the local area are more likely to undergo the biggest potential damage of conserving such a site for not allowing their development. Conversely, the farther away from the natural resources site accompanies with the higher willingness to pay. The general public doesn’t undergo the regulatory restrictions of protected area as such their willingness to pay will tend not to decrease, due to their concern for the nonuse or existence value of the site while the natural resources are well protected. Furthermore, distance elasticity of respondents closer to the site is higher than those farther away from the site. This means, the respondents’ willingness to pay living around the resource site will be more sensitive to the change of distance. As for total values of Kenting National Park, Changhua Coastal Wetland and Black-faced Spoonbill Protected Area are 9.4 billion, 8.2 billion and 5.1 billion respectively. Thus, total values of users are higher than nonusers under the influence of distance.