"To the extent that a Tobin Tax on speculative and derivatives financial transactions (currencies, CDS, CDO, etc.) "

M.G. In Progess with a post on two taxes:

"What we read on Greg Mankiw's Blog: Chu and Pigou is very promising. Particularly so if the next US Energy Minister said :"Somehow we have to figure out how to boost the price of gasoline to the levels in Europe". It is now quite clear that there is a compelling economic and logic case for applying this kind of Pigouvian taxes in the United States ( I AGREE ). They could also contribute to stabilize the energy markets promoting alternative energies and redistributing surpluses and savings, via reduced demand, from oil producers to consumers. On the other hand, just in July 2008 a price of oil at 150$ was factored in, with Goldman Sachs also predicting 200$, thus there is scope and room for a Pigouvian tax or import tariff up to the difference between the July and the present oil price. I am not personally convinced of any argument that oil market prices are established on the basis of supply/demand balance and all predictions are meaningless or biased. Nowadays' oil price is probably more than 60% pure speculation and manipulation.
To the extent that a Tobin Tax on speculative and derivatives financial transactions (currencies, CDS, CDO, etc.) could also be considered a Pigouvian tax levied to correct the negative externalities of some financial market activities and products, including Ponzi schemes, I think there is much scope, particularly in the United States, to take on the old proposal of Nobel Prize James Tobin. As we cannot afford to backslide to the voracious, "polluting" ways of financial markets and innovation as it did in the 1990-2000s, a financial transaction tax has several advantages and under the present circumstances I would not recommend it to make it that modest. ( I DO NOT AGREE )
It goes without saying that revenues from Pigouvian and Tobin taxes could offset other tax cuts or government spending to help redistribution of income and restructuring of the economy. "

To the extent that I understand a Tobin Tax, it would apply to all financial investments. Picking out a few investments to be taxed would likely serve to create other means to do the same thing via an untaxed investment. I do not believe that we want to interrupt the natural flows of investment. In fact, we should be encouraging investment. Taxing all investments because you want to penalize or hinder some investments is akin to creating a tax on all Energy in order to discourage the consumption of gas for automobiles. One could argue that the tax would go into a fund to aid financial concerns in the event of a crisis, but I suspect that this tax would have all kinds of problems, including not being used for what it was intended to be used for.