本研究利用歐洲能源交易所歷史價格資料,以GARCH模型分析2008年3月至2009年12月之二氧化碳排放交易價格波動現象(簡稱碳價格波動)。本文除考慮能源變數外,亦納入氣溫極端虛擬變數,其中能源變數轉換為波動形式或變動率形式,以了解各類能源對於碳價格波動究竟為何。本文實證結果概述如下: 一、未擺入能源變數落後期分析碳價格波動之實證結果: 煤炭價格波動、原油價格波動、發電廠採用天然氣發電報酬變動率,以及每單位碳排放之天然氣溢價變動率對於碳價格波動具正向影響。顯示使用上述能源,除能源需求上升帶動能源價格上升外,也帶動碳排放權需求上升,因此對碳價格波動有正向影響。 二、擺入能源變數落後期分析碳價格波動之實證結果: 當期能源變數對碳價格波動影響與上述相同外,落後期探討的部分:煤炭價格落後期波動與原油價格落後期波動,除對碳價格波動顯著影響,亦造成煤炭價格當期波動與原油價格當期波動有顯著影響。 三、未擺入能源變數落後期的探討,對於碳價格波動持續影響的程度,會大於擺入能源變數落後期的影響程度。
In this paper we use GARCH model to analyze the daily carbon prices volatility of European Union Allowances (EUAs) traded in the European Energy Exchange with a sample period from March 2008 to December 2009. We consider both the energy prices and two extreme weather dummy variables. Three empirical results were found. First of all, the coal price volatility, the oil price volatility, the CDS volatility and the Switch volatility have singnificant and positive effect on carbon price volatility without consideration of energy related lag variables. Secondly, the coal price volatility and the oil price volatility are significant in explaing the carbon price volatility by considering energy related variables. Finally, the volatility effect on carbon price without lags effect is larger than the effect with lags effect.