非意欲產出對國內機場經營效率及產出損失之影響

The Impact of Undesirable Output on Managerial Efficiency and Output Loss of Domestic Airports in Taiwan

機場為一具有多元投入及產出之生產單位，要衡量其經營績效，必須考量其多元投入及產出之特性，且必須能將此效率指標轉換為有效的管理措施。回顧過去對於機場經營績效之相關文獻，並無探討航空噪音管制對機場產出效率影響之相關研究；而機場之航空噪音為生產過程中不可避免之副產品。因此，本研究主要目的在提出一套評估機場經營績效的衡量方法，以及探討航空噪音對機場造成之潛在產出損失。由研究結果顯示，因國內機場因受到航空噪音相關法規之管制，將效率分析模式納入機場之航空噪音量後，效率值之大小及排序差異非常大，表示機場若將對周圍環境所造成之航空噪音污染納入績校評估，會打亂了機場彼此之間經營績效的排序及效率分數，此亦說明了評估機場的經營績效不能單就意欲產出加以評估。就考慮到航空噪音對意欲產出之衝擊而言，因航空噪音管制而必須犧牲其部分投入以處理所產生之航空噪音，所造成之潛在總產出損失相對於意欲產出極其微小，僅佔平均意欲產出的1.5%，說明目前政府對機場所作的航空噪音管制措施，就機場之生產活動而言並未造成太大影響。

The externalities generated from commercial flights have various impacts on air quality, noise, water quality, fuel consumption and energy, waste and the ecology. Noise nuisance is undoubtedly the most significant of these and has the greatest impact on the community surrounding the airport. However, when some outputs are undesirable, it may yield biased measures of efficiency if only “goods” are valued and “bads” are ignored. It makes sense to credit producers for their provision of desirable outputs and penalize them for their provision of undesirable outputs. In this paper, of major concern in airport performance evaluation for undesirable output is the aircraft noise. An ideal efficiency measure for assessing airport performance must take into consideration the negative impacts of undesirable outputs, and credits airports for reduction in aircraft noise and increases in other desirable outputs. In fact, most currently available airport performance measures treat multiple outputs by valuing goods and ignoring bads, that is, little or no account was taken with respect to aircraft noise. The main purpose of this study is to develop and implement a performance measure applicable in general multiple outputs setting in which production yields some outputs that are desirable outputs and others are not to explore how aircraft noise influence airport performance and their desirable outputs. In the subject of performance evaluation, the results show that, ignoring undesirable output aircraft noise increases both frequency and the degree of inefficiency, and distorts performance rankings. This confirms that airports facing relatively strict environmental controls will appear to have low efficiency relative to those having relatively lax controls when comparisons are based on the conventional approach. From the point of considering aircraft noise, the airports encounter smaller potential loss when weak disability of aircraft noise index is imposed in output efficiency measure model.