I admit I had not heard about the Gini coefficient before and am having trouble getting my head round what seem quite odd figures. How is it, for example, that countries like Nigeria or the Democratic Republic of Congo have better Gini scores than the USA and Thailand? Surely in both those African countries there is massive corruption and wealth concentrated in relatively fewer hands?

My first thought from a quick glance at the Wikipedia table above that you cannot just take the Gini score on its own. If you also compare Gini with Wealth Per Adult Capita, you find startling differences. The first figure in each column below lists the Gini score, the second the WPAC score -

Switzerland - .803 / $179,345
USA - .801 / $201,319
Sweden - .742 / $102,996
Nigeria - .736 / $2,070
Democratic Republic of Congo - .711 / $3,328
Thailand - .710 / $21,295

And surely the total adult population of a country needs to be taken into account?