The Gallup Organisation has just released its latest findings on where people would live if given a choice. This was a massive project, with 350,000 people interviewed in 148 countries over three years.
Not surprisingly, many in the poorest nations want to move to rich countries. Thus, 38 per cent of the people in West Africa want to emigrate. And the populations of Canada, the United States and Australia would increase substantially.
In Asia, however, there are some odd findings. While elsewhere in the world people want to relocate to developed economies, more people in Asia want to leave three of the region's five developed economies - South Korea, Taiwan and Hong Kong - than want to move there.
This must surely be a reflection of the political realities, as South Korea faces an unpredictable, nuclear-armed North Korea. Taiwan, too, faces an uncertain future, with the mainland insisting on reunification.
Hong Kong also presents an interesting case. It is very much a developed economy and attracts immigrants from the mainland, South Asia and even Africa. But, while many people may want to move to Hong Kong, an even larger number want to move out.
And so, according to the Gallup findings, Hong Kong would suffer a 12 per cent drop in population. The corresponding brain drain would be worse, at 28 per cent, as those who left would be better educated than those who arrived.
Japan's population, by comparison, would be stable. The country would have a slight gain in people (1 per cent) while suffering a 13 per cent loss in educated people. But while the population increase would be relatively small, young people would account for 23 per cent of this increase. This should be good news for Tokyo, as it considers how to tackle its ageing population.