The other places where mobility tends to be high are in conflict-ravaged countries like Iraq that have lots of internal displacement. By contrast, there's much much lower mobility in China, where the hukou system of household registration effectively prevents rural workers from moving to cities. The rate of migration there is less than 5 percent in the past five years.
A few other notable findings in the Gallup report: It's not surprising that a decent fraction of the moves are related to college and education — which explains why younger people are more likely to move and wealthier countries often have more internal migrants. Another big reason for moving is job-related. And those moves don't always pan out:
In Northern America, for example, internal migrants are more likely to participate in the workforce than those who have not moved. However, internal migrants are no more likely to be employed full time for an employer. They are more likely to be underemployed or unemployed than those who have not moved.
More recently, economists have found that the rate of migration in the United States has slowed down dramatically since the 1970s — a trend that continued through the Great Recession: "The interstate migration rate in 2011 was 53 percent below its 1948-1971 average, while the rates of moving between counties within the same state and of moving within the same county fell 44 and 36 percent, respectively, over the same period."
It's still a mystery as to why this is. As a recent paper from the Federal Reserve Board argued, neither demographics nor the recession nor the rise in underwater mortgages can explain the drop.
That paper's theory is that American workers increasingly have less to gain from moving for a new job — the wage boost that historically came with switching companies has declined over time. But that just creates a new mystery, since it's not clear why that wage boost is vanishing (a trend that, again, predated the recession).