The census shows declines over the past five years in Donegal (-1.5%), Mayo (-0.2%) and Sligo (-0.1%), while South Tipperary, Roscommon and Leitrim grew by less than 1 per cent.
“This reflects a policy by the EU to gentrify, rather than develop, the west of Ireland,” Dr Mac Gréil told the Irish Times.
The Maynooth University sociologist and Jesuit had forecast that uneven economic development would result in a drain from rural areas almost two decades ago.
His study Quo Vadimus, for the Tuam archdiocese in 1998, warned of the “Galway factor”, where massive growth in urban areas would suck lifeblood from smaller towns and villages.
“One of the reasons why Ireland failed as an economic unit after the 1801 Act of Union is that no cities were built west of the Shannon after that,” he said.
Local government has been “undermined” to the extent that people feel disenfranchised, and this was also a factor in the Brexit referendum in Britain, Dr Mac Gréil believes.
“Knock airport founder Monsignor James Horan once said all TDs in the west should unite and forget party differences after each general election. I think there is merit in that.”