I don't know his source for 1900 or whether it refers to deaths in 1900, or people alive. However, here is some useful context about this idea. The keyword for

I don't know his source for 1900 or whether it refers to deaths in 1900, or people alive. However, here is some useful context about this idea. The keyword for this phenomenon as used by the US Census is "Lifetime Mobility". It's calculated by comparing on long form census forms the given state of birth to the current residence. Obviously this doesn't take into account moving during one's life and moving back to one's hometown, so it's not entirely accurate for a measure of people who never leave home. It also has a very coarse granularity of state. In any case the finding was "Fifty-nine percent of people in the United States were born in their state of residence." Source: https://www.census.gov/prod/2011pubs/acsbr10-07.pdf https://www.census.gov/prod/2011pubs/acsbr10-07.pdf A 2011 Census analysis of migration data shows that mobility varies by region. At https://www.census.gov/newsroom/releases/pdf/2011-11-15_migration_slides.pdf https://www.census.gov/newsroom/releases/pdf/2011-11-15_migr... see page 22 and note that for all age ranges, 50% or more remained in their state. For the midwest and northeast though numbers are higher - about 60-70%. The West is the anomaly with much higher rates of in migration. On page 23 we see Louisiana has the highest number of people remaining in state, 78.8% and Nevada the least at 24.3%. On page 43 we see the information we are looking for. Century trends of those born in the same state they now live in from 1900-2010. This is fairly interesting and surprising. It shows a century of very little migration in Pennsylvania where 76% live and were morn there, but decreasing numbers for Florida, with 65.2% born and living there in 1900, but 35.2% living there also born there in 2010. A 2008 national phone survey went into more detail looking to break that state claim into those who never moved from their hometown at all. They found that "nearly four-in-ten — have never left the place in which they were born". Further along it explains in more detail "57% say they have not lived in the U.S. outside their current state: 37% have never left their hometown and 20% have left their hometown (or native country) but not lived outside their current state." http://www.pewsocialtrends.org/2008/12/17/who-moves-who-stays-put-wheres-home/ http://www.pewsocialtrends.org/2008/12/17/who-moves-who-stay... So, if the number in 1900 was actually 50%, it is 37% now for people who never move from their town of birth. A genetic analysis of strontium isotope ratios in early hominid teeth suggests that very long ago 90% of men stayed near where they were born, but 50% of females moved away to other areas. http://www.independent.co.uk/news/science/early-women-had-to-go-forth-and-multiply-while-men-stayed-home-2291999.html http://www.independent.co.uk/news/science/early-women-had-to...