| Summary: | 博士 === 國立交通大學 === 運輸科技與管理學系 === 92 === With the aim of capturing the essence of transit performance, this dissertation addresses four crucial but often neglected issues regarding efficiency measurement for bus transit industry, and thereby using a novel refinement of conventional DEA (Data Envelopment Analysis) models to deal with these issues, in order to shed new light on the facts relevant to transit performance.
In contrast to these four issues, this dissertation consists of four essays, with particular reference to the transit performance measure in Taiwan. The first two essays pertain to the impact of privatization on bus firm’s efficiency and talk about to what extent the various efficiency changes before and after privatization. The first essay applies a hyperbolic graph efficiency approach to measure “return to the dollar” at the station-level of Taiwan Motor Transport Company (TMTC) over the pre- and post- privatization period. This measure is further decomposed into its technical and allocative efficiency components. Price distortions can be measured by allocative efficiency using data on observed costs and revenues without requiring explicit information on prices.
The decomposition results indicate that both technical and allocative efficiencies contribute to the growth of “return to the dollar”, with the allocative component playing a more important role than the technical component. Perhaps in an attempt to cover the inefficiency-induced losses, both the public and private firms apparently resort to distorting relative output prices with respect to input prices, and the distortion is more pronounced in the private firm than in the public firm.
In the second essay, a directional output distance function which incorporates both desirable and undesirable outputs is employed to investigate the effects of privatization experienced by the TMTC. For the first time, the risk-adjusted efficiency change following privatization are estimated by treating transport risk as a joint but undesirable output. The empirical results demonstrate that TMTC’s privatization has produced a distinct improvement in efficiency enhancement and as such may be considered to be a source of cost reduction.
The last two essays shift the focus from investigating the influence of privatization on the transit firm to the efficiency measurement of some transportation organizations which engage in various activities (services) simultaneously. This third essay focuses most attention on the technical aspect of how to determine the efficiency of individual services within different but highly homogeneous multimode transit firms which engage in their services with non-identical technologies and use shared inputs. The empirical findings indicate that the multiactivity model used is more demanding than the conventional DEA model.
The fourth essay expands the analysis of the third essay to consider both the unstorable characteristics of transportation service and the technological differences within multimode transit firms. The proposed network DEA model allows a representation of both production and consumption technologies in a unified framework and thereby can be used to simultaneously estimate the cost efficiency, the service effectiveness and the cost effectiveness of multimode transit firms. The results obtained from the network model compared to those of a conventional model are quite different in terms of the number of efficient or effective units, rank comparisons of DMUs performance as well as inter-related effects. Throughout the dissertation, the non-parametric technique, also known as DEA, is used as the common approach which integrates the four essays into a dissertation.
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