If applied at the intermediate, netting stage of foreign exchange transactions, rather than at the initiation stage where the deals are made or at the final settlement stage when payments are completed, a properly designed Tobin Tax is feasible and can also be unilaterally imposed by any country on all foreign exchange transactions worldwide involving its own currency. If implemented, economic experts have estimated that the tax proposal could raise as much as $300 billion a year, based on 1992 estimates of daily currency trading of about $1.3 trillion.
2. Increased costs would cause pension funds and other portfolio managers to increase their home bias. Less capital would be available for international capital markets.
3. A Tobin tax would not prevent speculative attacks on a currency where the expected gain might be high. It could not replace unsustainable economic policy - usually the main reason why a currency comes under attack.
4. The tax would be impracticable since it would require worldwide coverage, or at least coverage encompassing the G10 countries, supplemented by a penalty on transactions to tax havens. Unilateral implementation would move currency trading offshore.
5. The tax would throw sand in the wheels of international trade and investment and would harm the prospects for raising global economic growth and the welfare of all peoples. Far from helping developing countries, the tax would hurt the smallest nations most.
6. The tax would not prove feasible in practice since it would require uniform implementation throughout the world and would need to encompass, not only spot transactions, but also substitutes and supplements such as currency swaps, forwards and futures, in order to limit evasion.