For a country that's short of cash and repelled by Wall Street greed, this proposal sounds like a winner: Tax the sale of stocks and bonds. At a penny for every $2 worth of securities, such a levy would bring in about $12 billion a year. And it would fall most heavily on the fast-buck artists who buy and sell securities for speculative gain, not long-term investment. Or so the pitch goes.
Unfortunately, even though the tax sounds small, it probably would jolt


