排放權市場交易資訊成本分析──以高屏空品區氮氧化物管制為例

Information Costs for Transaction in Tradable Permit Markets - A case study of Nitrogen Oxide control in Kao-Shiung and Ping-Tung Counties

空氣污染的改善將會對工業、農業及家計部門產生正面的影響，因而本文以環保署預計在高屏地區所推行的氮氧化物排放權交易制度為例，探討因市場資訊不充分而衍生的交易資訊成本為何？本研究首先利用成對及連續交易之方式來模擬廠商在市場的交易狀況，並設定數種可能交易情境來估計達成污染管制目標所需之社會總減量成本，並將此與完全競爭市場架構下的成本進行比較。研究結果顯示，當減量目標設定為民國89 年排放水準的90%時，社會總減量成本在完全競爭結構下為2,593 萬元，而在成對及連續交易方式中，以「邊際成本最高廠商與最低者優先交易」之情境可達較低的總減量成本，但仍有3,292 萬元，而兩者間的差距699 萬元則可歸因於廠商在交易過程中因資訊不充分所衍生的額外成本，因此政府應藉由揭露更公開的各產業減量成本資訊及排放量資料，來誘導邊際減量成本差距大的廠商優先進行交易，以降低廠商在排放權交易市場中的減量成本。

Using a newly proposed tradable permit market for Nitrogen Oxidecontrol in Kao-shiung and Pint-tung area as an example, this researchtries to estimate the potential information costs for permit trading duringthe sequential and bilateral transaction process when firms are requiredto reduce their emission by 10% of the year 2000 baseline levels. Theresults show that the total costs governed by the rule where firms thathave the highest and the lowest marginal abatement costs are managedto trade first could be $6.99 million higher than the costs under a perfectcompetition market structure. The difference could be attributed to theincomplete information among participants in a new trading market. Thecontrol agency under this circumstance should try to close the gapthrough releasing more information of cost structure in each industry andemission records of firms.