I have to say, I'm surprised to see the ACS combine Yiddish and Other West Germanic languages in the 2012-2016 ACS data (table B16001). "Other West Germanic" speakers tend to be Pennsylvania Dutch/Amish groups. The groups that speak these two languages couldn't be more distinct (aside from being religious communities that don't use electricity some or all of the time, grow big beards, and wear black hats).
Practically, it probably won't be hard for people to distinguish whether local populations are Hasidic Jews or Amish, since these groups tend to be in distinct areas like Brooklyn and central Pennsylvania, with little overlap. But given the cultural differences, I wish they hadn't been combined; it will no longer be possible to find the areas with the largest concentrations of Yiddish or OWG speakers in the country.
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