I started off with what seemed like a simple question: Which states have the greatest coverage of professional genealogists, and which have the least?
It sounds like a simple enough question. The Association of Professional Genealogists (APG) has an online membership directory. Each member can list a profile describing his/her specialties, including up to twelve “Geographic Specialties.”
When I tally the number of genealogists per state, I got this:
Or, if you prefer, in map form:
So New York (206) is the subject of the most professional genealogical specialists, followed by Pennsylvania (174) and Massachusetts (135). Hawaii (6), Nevada (6) and Wyoming (6) have the fewest. End of story.
But hold on. This does not really answer my original question, which was about the “greatest coverage of professional genealogists.” Surely we must factor in the population of the state to see what the coverage is. So I redid the above two charts, this time looking at the number of professional genealogists per 100,000 population, using population data from the 2010 census. This yields the following two charts:
Interesting. The states with the most genealogists specializing in them per 100K population are Vermont (8.9), New Hampshire (4.9) and Delaware (4.8). The states with the fewest are California (0.3), Nevada (0.2) and Florida (0.2).
This one had be scratching my head a bit. Why is Florida so low, for example? Anyone who went to the NGS conference earlier this year in Fort Lauderdale saw the massive turnout from Florida genealogists. So what’s going on here?
Then it struck me — the thing that really counts, from a genealogical perspective, is not where people live today, but where our ancestors lived in the past. That is why, as a research subject, Virginia and a bunch of small New England states hugging the east coast can have a genealogical significance that outstrips even mighty California and Florida. But how to represent this historical significance?
What I decided to do is give equal weight to all of the decennial censuses, from 1790 to 2010, to create what I’m calling “normalized historical population.” Think of it as calculating the proportion each state’s population in each census, averaging these proportions, and then normalizing it to the current (2010) total national population. This allows us to do more of an apples-to-apples comparison, of how our current population distribution is versus what a time-averaged U.S. population distribution would like.
Here first is the current (2010) population distribution, showing, as we all know, that California, Texas, Florida and New York are the high population states:
And then here is the normalized historical population version, showing the influence New York, Pennsylvania, Ohio, Virginia and Massachusetts had as historical population centers.
Now we have the data to take the next (and last) step to answer the question, “Which states have the greatest coverage of professional genealogists, and which have the least?” I looked at APG members per 100K “normalized historical population” to get the following two charts:
The states with the most coverage are Alaska (4.0), Utah (3.4) and Delaware (3.1). Those with the least are Mississippi (0.7), New York (0.6) and Louisiana (0.6).
So what does it all mean? I can think of reasons why Utah would be high. But why Delaware? And why is Louisiana so low? Please, feel free to share your thoughts.
Note: This post has been updated to include Washington, D.C., which was inadvertently omitted in the original post.
8 September 2016 Addendum
I’ve receive a few questions about international APG membership and why I left them out. A few words on this subject are appropriate.
At a coarse level, of course we can total how many APG members (with profiles in the APG directory) are from each country:
But taking it further than this, such as calculating genealogists per 100K population, would require extending some assumptions that may be true for United States genealogists, but are unlikely to be true worldwide. In particular, behind all the United States charts is the assumption that although not 100% of professional genealogists are APG members, a good proportion of them are, and that proportion is unlikely to vary much from state to state. So if, hypothetically, 70% of professional genealogists in the United States are APG members, then I’d expect this to be true in California as well as Rhode Island as well. It seems implausible to me that this assumption would hold in other countries, i.e., it is unlikely that 70% of professional genealogists in the UK or in Germany are APG members. Given that, international comparisons would be meaningless. That is why I did not extend the calculations worldwide.