The island's unique social and economic organisation has evolved over the years, but is based on the principles set out by William Glass in 1817 when he established a settlement based on equality. All Tristan families are farmers, owning their own stock and/or fishing. All land is communally owned. All households have plots of land at The Patches on which they grow potatoes. Livestock numbers are strictly controlled to conserve pasture and to prevent better-off families from accumulating wealth. Unless it votes for a change in its law, no outsiders are allowed to buy land or settle on Tristan; theoretically the whole island would have to be put up for sale. All people – including children and pensioners – are involved in farming, while adults additionally have salaried jobs working either for the Government, or, a small number in domestic service, and many of the men are involved in the fishing industry, going to sea in good weather. The nominal fishing season lasts 90 days; however during the 2013 fishing season – 1 July through 30 September – there were only 10 days suitable for fishing.

What is based on principles put into place by William Glass in 2013?