氣候法案的理論分析.doc

Wonky Talk about Carbon Taxes qianlaoda譯I appreciate David Leonhardts kind words about my recent Times column on the problems with giving away, rather than auctioning, carbon allowances. I thought it might be useful to explain a bit more some of the economics behind what he calls my Rorschach test. Here is the more wonky way of putting some of the arguments.感謝David Leonhardt。我最新的紐約時報專欄上討論了“二氧化碳配額”的分配（而非拍賣）的問題，他給予了善意的評價1。我認為，就他所說的“曼昆的羅爾沙赫氏測試”背后的經(jīng)濟學，給予多一點的解釋，可能還是有意義的。下面是一些比較書生氣的解釋，來說明我的一些觀點。We can think of the typical household as having to make two decisions. First, the household decides how much to work and consume. This is the standard consumption-leisure tradeoff. Second, the household decides how to allocate consumption between carbon-intensive products and less carbon-intensive products.我們可以設(shè)想，典型的家庭必須進行兩個選擇。第一個選擇是：家庭必須決定工作量和消費量。這是標準的消費-閑暇權(quán)衡模型。第二個選擇是：家庭要決定在二氧化碳的關(guān)聯(lián)產(chǎn)品和非二氧化碳關(guān)聯(lián)的產(chǎn)品上的消費分配。Mathematically, we might write utility as數(shù)學上，我們可以將效用記為如下形式：U = u(C) + v(L)where C is consumption and L is leisure. Consumption is a composite of carbon-intensive consumption C1 and less carbon-intensive consumption C2, which we can write as其中，C為消費量，L為閑暇量。消費包括“二氧化碳關(guān)聯(lián)產(chǎn)品”的消費量C1 和“非二氧化碳關(guān)聯(lián)產(chǎn)品”的消費量C2, 因此，消費就可以寫為：C=F(C1,C2).There are two margins of adjustment: between C and L, and between C1 and C2.存在兩個邊際調(diào)整：C和L之間，以及C1和C2之間.We start in a situation in which each of these margins of adjustment is distorted. Because earnings are taxed via income and payroll taxes, people have too little incentive to work and consume. In addition, because there is a negative externality associated with carbon, people have too little incentive to move their consumption basket toward less carbon-intensive products. In other words, the relative price of consumption compared to leisure is too high, and the relative price of carbon consumption compared to noncarbon consumption is too low.我們的初始狀態(tài)是：這兩個邊際調(diào)整，每一個都是扭曲的。因為人們的所得有兩種稅收：收入稅和工資稅，所以，他的工作激勵和消費激勵是非常小的。同時，因為存在“二氧化碳的負外部性”，所以，人們的消費轉(zhuǎn)為“非二氧化碳關(guān)聯(lián)產(chǎn)品”的激勵，也非常小。換言之，消費相對于閑暇的相對價格，是非常高的；而且，“二氧化碳產(chǎn)品”的消費相對于“非二氧化碳產(chǎn)品”的消費的相對價格，也是非常低的。The trick is how to fix the second distortion without making the first one worse. A tax on carbon with the revenues used to cut income taxes does that. Everyone who thinks there are negative carbon externalities should agree that is the efficient policy.關(guān)鍵在于：如何能固定第二種扭曲，而不使得第一種變得更差。對二氧化碳征稅，并將稅收收入用于削減收入稅，就可以實現(xiàn)這個目標。每一個認為“存在二氧化碳的負外部性”的人，都應該會知道：這就是有效的政策。A tax on carbon with the revenue squandered via lump-sum handouts to powerful special interests, however, fixes the second distortion but makes the first one worse. The good thing about this policy is that it raises the price of carbon-intensive consumption relative to less carbon-intensive consumption. The bad thing about it is that it also raises the price of consumption relative to leisurein other words, it depresses the real wage. The basic problem is that a new tax on carbon-intensive products C1 is also an additional tax on consumption C, unless there is some other offsetting tax change.然而，對二氧化碳征稅，但是，稅收收入?yún)s通過一次性地將配額轉(zhuǎn)移給“有權(quán)勢的特殊利益群體”而分散，就是“固定了第二種扭曲”卻使得第一種扭曲變得更糟糕。這種政策的好處在于：它提高了“二氧化碳關(guān)聯(lián)產(chǎn)品”消費相對于“非二氧化碳關(guān)聯(lián)產(chǎn)品”消費的價格。它的壞處在于：它也提高了消費相對于閑暇的價格換言之，它壓抑了真實工資?；镜膯栴}就是：除非存在一種抵償性的稅收變化，對二氧化碳產(chǎn)品C1的新增稅收，也是對總消費C的新增稅收。This is where the Rorschach test comes in. A carbon tax without a compensating income tax cut makes one problem better and one worse. The question then is which problem is bigger. I dont think there is a consensus among economists on this last question. That is why reasonable people can disagree about the bill being debated in Congress.現(xiàn)在，羅氏測試就出現(xiàn)了。對二氧化碳征稅，卻不進行補償性的收入稅的消減，使得一種問題變好，又使另一種問題變差。這時的問題就是：哪一個問題更加大一些？我認為，在這個新問題上，經(jīng)濟學家之間并不存在共識。這就是理性的人們并不同意正在國會討論的那個法案的原因。But there is a consensus, more or less, that we could fix one margin of adjustment without distorting the other margin more. But that requires a cut in income or payroll taxes to be a key part of the environmental policy. 但是，差不多還是有一個共識的。即：我們可以固定一個邊際調(diào)整，而不使另一個邊際調(diào)整更加扭曲。但是，這就需要對收入稅或工資稅進行削減，這就是環(huán)境政策的核心部分了。注釋：1. 關(guān)于善意評價。即：無論你自己位于哪個陣營，我也要推薦曼昆的專欄。他的模型使人能理解復雜的