The latest mantra from development specialists is concern about the future availability of water. It is an old topic but a durable one given the preciousness of the resource. Since 70 percent of the withdrawals of freshwater around the world are for agriculture, and 60 percent more food must be produced based on population growth, it is an understandable focus. It means a large increase in the trading of “virtual” water as food is moved from where it can be produced to where it is needed for consumption.  The U.S. and EU are major agricultural producers and exporters due to the large availability of both arable land and water. China and particularly India are also well-endowed but have large domestic demand for food and wa...