The world needs a single global currency for at least ten reasons:

1. Eliminate the direct and indirect transaction costs of trading from one currency  to another.
2. Eliminate the Balance of Payments/Current Account problems of all countries.
3. Eliminate the risk of currency failure, currency risk.
4. Eliminate the uncertainty of changes in value due to exchange-caused fluctuations in currency value and the costs of hedging to protect against such fluctuations.
5. Cause an increase in the value of assets for those countries currently afflicted with significant country risk.
6. Eliminate the misalignment of currencies. 
7. Utilize the seigniorage benefit and control of printing money for the operations of the global central bank and for public benefit.
8. Eliminate the need for countries or monetary unions to maintain international reserves of other currencies.
9. Reduce worldwide inflation to a planned low rate of approximately 2% and thereby ensure low loan interest rates.
10. Confirm or implement a basic, fundamental human right, as noted by Ludwig Erhard, just as is the fundamental human right to own property. 

1. Transaction costs. Every day, more than 1.4 trillion dollars of currencies are traded on the foreign exchange markets and every transaction cost something.  It’s estimated that the average cost of all transactions, including all the staff and equipment, is .33%, or approximately $1 trillion per year. Although .33% is a small percentage, $1 trillion is a lot of money in a world where millions go to bed hungry every day.

       In addition there is an indirect cost with every transaction of time, inconvenience and mistake.

2.  Balance of Payments/Current Account.   Every country or monetary union must cope with the problem of ensuring that international payments balance, becasue imbalances tend to cause fluctuations in currency values, currency risks.   While often stated as a "trade" problem, the Balance of Payments or Current Account problem is only a problem caused by the existence of multiple currencies.  Within monetary unions, there is no balance of payments problem among the member countries or states.

3. Currency Risk. Part of the built-in price of every currency is the risk that it will fail. Perhaps that’s the risk that the government will fall or that a primary industry sector will fail, or that a natural disaster will be hugely expensive. If such events are expected or even feared, the discount of that country’s currency will increase, i.e. the currency will be worth less. For the people within that country their savings may be exposed to complete loss.

4.  Uncertainty of changes in value.  Hundreds of billions of dollars are spent annually coping with exchange-caused fluctuations in currency values.   Reports of corporations are corrected for changes in value, and all international economic reports need to be similarly adjusted.  For economic transactions occurring over time, there are often costs of hedging to protect against such fluctuations.  

5. Asset Value. When currency risk is minimized the only obstacle to residents and foreigners investing in a country is the actual risk of the failure of the venture. For many countries where the currency risk is more than the expected annual return on the investment, investment is totally blocked. However, if the currency risk were to be eliminated, at least down to the level of low inflation of the single global currency, investments would be much more appealing. Several articles and books have shown how asset values began rising in Europe in direct relation to the increasing likelihood that the euro would actually be launched.

6.  Misalignment of currencies.  There are many ways that countries compete with one another and one way is by adjusting the value of a country’s currency relative to others.  Often this is done to increase exports.   Direct and indirect manipulation of currencies for national advantage is not a fair tool of international trade.

7.  Seigniorage Benefit.   The Global Central Bank would be financed by whatever benefits will come from the printing of money and seignniorage.   Any surplus monetary additional benefits coming to the bank would be allocated to politically agreed-upon goals, such as the reduction of foreign debt or the eradication of disease or the support of family planning or other shared world goal.

8.  International reserves.  Currently, each of the world’s currencies maintains reserves of other currencies  in order to finance trade, but also to ensure trust in the value of the "reserving" currency.    While a Single Global Currency will likely need some form of "backup" or "reserve" to ensure and protect the people’s all-important trust, such a backup or reserve will not include other currencies, by definition.

9.  Inflation/Borrowing Interest Rates.  Inflation now varies among currencies, but is more stable and consistent within a monetary union.     Among economists and Central Bankers, there is some affinity with an inflation rate of 2%, and it is the goal of the European Central Bank among others.   With such a low inflation rate, interest rates can be stabilized at relatively low rates, as well.

With worldwide inflation and interest rates being roughly consistent, it will be interesting to see the effect on worldwide capital flows.

10.  Fundamental Human Right.  Former German Economics and Prime Minister, Ludwig Erhard proclaimed that "monetary stability was a basic human right". (see "Different Monetary Systems: Costs and Benefits to Whom?" by Jose Luis Cordeiro.)  The Single Global Currency Association will be urging that the United Nations and other groups recognize monetary stability as a fundamental human right.