Dhananjayan Sriskandarajah, co-author of the report, said that the scale and spread of the British expat diaspora was probably being driven by the UK's economic strength.
A strong economy was attracting economic immigrants - but also encouraging Brits to broaden their opportunities.
"Britain is truly at the crossroads of the global movement of people," said Dr Sriskandarajah.
"Two-thirds of Britons who leave do so to seek employment abroad - and are replaced by skilled professionals from elsewhere in the world.
"When the going is good, Brits get going."
Ironically, significant outmigration is characterized as an indicator of a strong economy. That wasn't the case for Pittsburgh during the 1980s, but the best and the brightest were (and are) the most able to seek better opportunities elsewhere. The crux of the problem is that many Western Pennsylvania towns and cities are unwilling to cultivate immigration flows.
Regardless, the Institute's report on the British Diaspora is another example of a public policy direction Pittsburgh should mimic. The Burgh Diaspora deserves more study and Pittsburgh should endeavor to formalize the migration flow and emerging network.