A complicating factor is that merit aid has become so popular with middle-income families, who don't qualify for need-based aid, that many have come to depend on it.
The complexity of these relationships makes it unlikely that a system of import relief laws will meet the strategic needs of all the units under the same parent company.
The ancestors of the modern Zuni and Hopi built and then, for reasons still mysterious, abandoned the complex roads and structures of the domain they ruled a millennium ago in the American southwest.
Dr Neil Da Costa, who presented his research on the Bloody Mary at a meeting of the American Chemical Society yesterday, said, "It's a very complicated drink."
After the fall of Rome, the first European society to regulate behaviour in private life in accordance with a complicated code of etiquette was twelfth-century Provence, in France.