We have laws against monopoly but not against monoculture, which is an even greater threat to freedom and diversity - both biodiversity and cultural diversity. I remember one day in the late 1980s watching with dismay while some beautiful 19th-century stone-built terraces, planted with a mixture of apricot and almond trees and vines above the Douro river at Quinta do Noval in northern Portugal, were bulldozed to make way for the new-style monoculture port wine vineyards.

The owner at the time, Cristiano van Zeller, understood what was being lost but felt he had no alternative; everyone was doing the same (many with World Bank loans) and the profits were so much higher. What he and others did not realise was that the new bulldozed terraces were far more vulnerable to soil erosion.