• 作者： 蕭銘雄; 彭信坤; 李治綱
• 作者服務機構： 國立成功大學交通管理科學研究所;中央研究院經濟研究所
• 中文摘要： 一般常見之車輛持有時間序列模式，因無法處理國內小汽車與機車等多運具並存現象，在應用上受到相當的限制。本研究利用「擴散(diffusion)」概念推導出之多運具競爭車輛持有模式，與傳統多元迴歸模式或羅吉斯特模式比較，有兩大特點：（1）以資訊擴散觀點解釋人們車輛持有行為之交互影響，並據以推導運具持有率模式；（2）考慮多種運具彼此競爭，可解釋國內小汽車與機車等多運具並存現象。 部份民眾在法律規範或購買能力等因素之限制下，無法持有機動車輛，因而造成車輛持有成長之飽和值，成為一種擴散範圍之限制。本研究以三種不同假設推導模式：第一種不考慮擴散範圍限制；第二種假設各運具面臨相同之擴散範圍限制；第三種假設各運具面臨不同之擴散範圍限制。此三類模式經以台灣地區資料驗證其可行性，分析結果顯示第一、二種模式因隱含時間趨勢，反應社經變數較為理想，短期預測能力亦較佳；第三種模式經差分後失去時間趨勢，無法確切反應社經變數，短期預測能力不佳。就長期趨勢而言，第二、三種模式因各運具持有率可趨近不同之飽和水準，而顯得較為合理。
• 英文摘要： Cars and motorcycles are two popular transportation modes for travel in Taiwan. Most widely usedtime series models cannot simultaneously analyze this situation of multi-class motor vehicle ownership. Thisstudy derived several multi-class ownership models on the basis of a diffusion process of vehicle ownershipbehavior. They represent the change of ownership as a function of vehicle information diffusion amongpeople, describing the substitution relation between transport modes explicitly, and can be used to predictmotor vehicle ownership trends simultaneously. Three types of models were established in consideration of the growth saturation level. First, un-constrained diffusion models (UC-DM) do not include any restriction on the diffusion process. Second,total market constrained diffusion models (TMC-DM）consider one saturation level for all modes. Third,specific market constrained diffusion models (SMC-DM) consider different modes with different satura-tion levels. An empirical study using these models has been done based on registration data for cars and motor-cycles in Taiwan. UC-DM and TMC-DM provide good statistical results that have explanatory abilityfor socioeconomic variables and short-term predictions. TMC-DM and SMC-DM are likely to be reasonableat predicting long-term trends.
• 中文關鍵字： 車輛持有; 擴散; 羅吉斯特模式
• 英文關鍵字： --