An Empirical Investigation into the Effects of Gas Price and GDP on Freeway Traffic

• Main Authors: Yang, Shu-Chin, 楊淑津
• Other Authors: Chiou, Yu-Chiun
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/51875562064923060241

碩士 === 國立交通大學 === 管理學院碩士在職專班運輸物流組 === 98 === It is a concept universally acknowledged that when gas price rises, the toll road use will reduce. It is also well-fixed in the minds of many policy makers that they devise energy-related policies based on this premise. With an aim to successfully implement the government’s proposed green tax policy for achieving certain levels of environmental protection by increasing the gas price to reduce the usage of vehicles, the causal effect of gas price and traffic volume plays a significant role here. As a result, this study takes a closer look at the conceptual grounds of the notion of causality in Granger’s sense. In addition, taking into account that GDP may be also a key component of affecting vehicle usage, it is also incorporated into the study. Cointegration test for the long term equilibrium relationship, Granger causality test for the short run lead or lag relationship and the analysis of impulse response function are employed to unveil and justify the linkage among the interested variables. The main findings are not in line with what we used to take for granted that no co-integration for the long run, not all the gas price or GDP Granger cause traffic volume and as well as some positive impulse responses of traffic volume to gas price shock and GDP innovation. However, as even the simplest descriptive statistics can be deceptive, our findings must be treated with caution especially when extrapolating any anticipated effects on relative policy making.