Join the Club

In reaction to this, I’m ready to join Greg Mankiw’s Pigou Club (people who support Pigovian taxes on carbon-based energy to deal with global warming – or other detrimental external effects of energy consumption – in an efficient way). There are a few reasons I might not be accepted, though:

1. I’m not sure that anonymous bloggers are qualified for admission.


2. I have to confess that my rationale is not 100% Pigovian. It seems clear to me that, even if Al Gore is only a little bit right about the causes and consequences of global warming, the optimal Pigovian tax is extremely high – much higher than what would be politically feasible (in the US) even in my wildest dreams. Energy demand is just not elastic enough, even in the long run, and the social costs of global warming are too high. So, for practical purposes, I see any increase in energy taxes more as a nondistortionary tax than as a Pigovian tax. There is a standard argument that taxes don’t do any harm if they don’t change behavior; in this case, changing behavior is gravy. (As for global warming, well, I’m just glad I’m going to die in another 40 years or so.)


3. I’m not sure Greg Mankiw reads my blog regularly enough to catch this post.

The argument commonly advanced against Pigovian taxes is that we cannot measure the relevant quantities well enough to ascertain the optimal tax. For example, in the (Toronto) National Post article linked at the beginning of this post:

The problem with a Pigovian gasoline tax is that it means using the same tools that failed planners everywhere over the past century. None of this stuff is measurable. What is the planned reduction in gasoline consumption? And what's the price to be set at? How high will the tax have to go before it changes behaviour enough to reduce demand? Will the government just wing it and see what happens? Will the alternative behaviour be any better or create new externalities and unintended consequences? What does government do with the money collected -- except launch a program of subsidies and spending to run alternative economic initiatives?

Since I’m convinced that the optimal tax is much higher than what is politically feasible, the uncertainty about the exact number is not a problem for me: I just advocate the highest tax possible. More generally, though, one might always set some reasonable lower bound and argue that the tax should be at least that high. The Post’s argument, as I commented in Greg Mankiw’s blog post (linked at the top), is essentially saying that government is generally incompetent, so whenever there’s a problem that the private sector can’t fix, the only reasonable approach is to ignore the problem. And then I proceeded to apply the same logic elsewhere:

The problem with using government-supplied police officers to protect citizens from crime is that it means using the same tools that failed planners everywhere over the past century. None of this stuff is measurable. What is the planned reduction in crime? And what are the wages of police officers to be set at? How much of this so-called police protection will have to be supplied before crime is sufficiently reduced? Will the government just wing it and see what happens? Will the police forces be any better than criminals, or will they create new externalities and unintended consequences? Where will the government get the money to pay these police officers?

I realize that a few anarchists won’t regard this as a reductio ad absurdum, but I’m not an anarchist myself. The debate does continue, however, and you can read it in the subsequent comments to Greg Mankiw’s post.