March 17, 2015
In a conveniently timed piece, Pew Research's Fact Tank blog released some statistics about the number of Americans with Irish heritage for St. Patrick's Day.
The percentage of the population – as well as the total number of Americans – who identify as such is still large:
In 2013, 33.3 million Americans, or one-in-10, identified themselves as being of Irish ancestry, making it the second-largest ancestry group in the U.S. after Germans.
But it is dropping:
Two decades ago, in 1990, 38.6 million Americans (15.5% of the total population) claimed Irish ancestry, and 5.6 million (2.3%) identified as Scotch-Irish.
What's important to note is that this is using census data, which relies on self-reporting. So while the number of Americans who say they have Irish heritage has dropped, that could be due to other factors. Mainly, if there are those actually with Irish heritage who simply don't know it, or are misinformed about their own heritage, that could account for some of the decline. That, obviously, is a much harder thing to measure.
Also, the post notes:
The Census Bureau has asked Americans to identify their ethnic ancestry since 1980, and annually since 2005. Because they can pick one or two, we counted everyone who chose Irish or Scotch-Irish as their primary or secondary ancestry.
Essentially, for people who are "mutts" so to speak (those with multiple ancestries), if they consider Irish to be their third or fourth most prominent ancestry, it may account for some of the decline as well.
Locally, Irish heritage continues to be strongly represented, and well above the national average. In Pennsylvania, according to Pew, 16.6 percent of the population identifies with having Irish ancestry, which is seventh most in the country. In Philadelphia, the number is 11 percent, making it the highest among countries of origin in the city.