虧損補貼對公路汽車客運路線營運績效之影響

Investigating the Relationships between Efficiency and Operating Subsidies in Inter-city Bus Routes

本研究透過隨機邊界分析法發展Translog生產函數，從公路客運路線生產結構探討成本效率、成本效果和服務效果三面向之路線營運績效，並考慮虧損補貼制度以及其他因子對模式估計效率的影響，採一階段方式估計模式參數，並採用二階段殘差介入法考量投入、產出與服務之間的潛在內生關係。研究結果發現，虧損補貼金額越高的路線，其路線成本效率越高，但服務及成本效果卻越低。研究結果亦顯示，在控制住環境因子後，公司間成本效率和成本效果有顯著差異，表示公司內部經營會顯著影響效率。路線特性如路線長度、班次數在現行法規下若提供更長、更多的供給，部分路線效率值有較高的情形，而受限搭乘者人口數越多，與成本效率值呈現負向相關。

To examine the operation efficiency under current subsidy schemes, the study developed stochastic frontier analysis (SFA) models specified in the translog functional form based on route-level data; in particular, three SFA models, focusing separately on cost efficiency, cost effectiveness, and service effectiveness, were developed. The study applied a one-step approach to simultaneously estimating the cost function and the effect of external factors on operation inefficiency for inter-city bus routes. A two-stage residual inclusion approach was also adopted to examine the potential endogenous relationship between route outputs and route services. The analysis results showed that operation subsidy was positive to the cost efficiency of routes and negative to their cost and service effectiveness. The results also showed that route operation performances were heterogeneous among operators after environmental factors were controlled. On the other hand, the study confirmed that route characteristics (e.g., route length, and service frequency) and environmental factors (e.g., potential captive riders) were significant to route operation performance.