Has the time come for the US to impose a financial transactions tax? It would have several positive features. First, it would raise revenues, which are sorely needed for everything from climate change action to infrastructure improvements to aid for needy families. Second, it would raise revenues from those who are most responsible for the financialization of the economy--investment bankers, fund managers, and high speed traders interested in bigger and bigger profits no matter the result for ordinary folks. Third, it would act in some small way to discourage excessive trading that contributes to the volatility of the stock market.
Of course, such a tax (frequently called a "Tobin Tax" after the Nobel economist who recommended it) would be best if applied by all sophisticated nations. It appears that the European Union is getting closer to making a financial transactions tax a reality in at least some of the participating countries. See James Kanter, Tax on Financial Trades Gains Support in Europe, New York Times (Oct. 10, 2012). Britain will remain exempt so the City of London (Europe's parallel to Wall Street) would continue on its merry way (or even increase the financialization of the UK economy as trades moved from participating countries to London). Wall Street has lobbied heavily against any tax on its activities, and would fight bitterly if the US were to impose such a tax while London remained exempt.
So my guess is that even if the EU finance ministers approve the measure for some participating European nations, it will take some time before it spreads to Britain and the United States. Like climate change, we seem determined to put off addressing real problems until they are upon us with such force that we cannot possibly continue as before. Thus, our financialized economy rocks along pretending that derivatives are safer and banks are fine and life can go on as before, and Congress debates climate change as a "she said, he said" matter rather than looking at the breadth and depth of scientific evidence supporting man-made effects that are reshaping the globe while we watch.