Quote from seasideheights:
the tax would encourage long-term investment while discouraging what he called âchurningâ
I'm afraid it is just wishful thinking - normative economists are again trying to save people from their (our) bad habits. In reality taxing capital creates a clear incentive to reduce its use. And even stock investors can reduce capital use with ease by increasing the very thing Tobin tax proponents want to reduce - volatility.
For a day-trader the choice between a standard ETF and its version leveraged 2:1, which would require only 50% capital to achieve the same returns, is rather obvious. So if the Government does not ban leveraged ETFs, short-term traders will switch to these vehicles, reducing aggregate market turnover and transactions tax base accordingly.
But it gets even worse with long term fund investors. They cannot use leveraged ETFs, because of the obvious time decay (synthetic theta bleed) associated with long-term performance of these derivative-like 'stocks'. So instead long-term investors will go for the most volatile funds: foreign commodity producers and foreign emerging markets funds. In preference to established, blue-chip American companies, Tobin tax would create an incentive to seek out the most volatile, smallest *foreign* markets and track their indices... making it increasingly difficult for US exchanges to attract new capital (with foreign markets offering better exit returns for early stage investors such as private equity funds). And all that just to maximize volatility of the invested capital, because that would reduce the Tobin tax liability.
Even active fund managers are likely to prefer more volatile stocks when they start being punished for their annual turnover. Their elusive alpha will be attacked from three fronts: through increased bid/ask spreads (any exemptions here would be impossible), tax on their non-exempt transactions, and increased preference for risk taking (which decreases risk-adjusted returns, e.g. the abovementioned alpha).
Last but not least, running an actively managed mutual fund creates more jobs than running a passive index fund or an ETF. Stock analysts jobs created by active management firms scale much more slowly than ETF capacity. Passive investment strategies scale almost automatically, requiring only minor changes in software development teams and server support staff, these days mostly offshored anyway. So the Tobin tax would target the very place which creates most jobs in the US investment industry, while channelling money to the Japanese-style 'fund factories' (run mostly by banks), ETFs which can be run by the same numer of software engineers, regardless of the fund turnover.
Need I only mention that job creation was supposed to be one of the official selling points of this tax... How many investment companies did it require to saturate the market with ETFs? And how many actively managed fund companies are there in the States with how many employees? Ask yourself these questions dear Mr Silvers before you praise a tax on ineffective 'stock churning' ever again...