The listener letter last week asked about the the three "red dots" that are used to identify liquor stores in South Carolina. Turns out that this kind of "shibboleth" is a way of identifying and discriminating, in ways that can be useful, or harmful. Red Dots in South Carolina: The Robert Moss (SOUTHERN SPIRITS) versionSouth Carolina Encyclopedia (from Moore, John H. “Solving the Red Dot Mystery.” Sandlapper,  spring 2000: 32–34.)Shibboleth Gileadites and EphraimitesBackground on the conflictNaked mole rats use shibboleths (thanks to Robert Lawson, who knows him some mole rats)The Stone Signposts of Pompeii World Series as Shibboleth  (Robert T. Gravlin, 23rd Armored Engineer Battalion) Appropriate Measures of Inflation ERRATUM: MJ writes to point out that if the economist could really count, he would have miscounted the number of sheep, adding one, because he counted the dog. That's fine. But then why did the shepherd agree that the number of sheep was correct? It should have been one over. It's okay that TWEJ's are not funny, that comes with the territory. But in this case there is a logical problem. My mistake, and thanks, MJ! If you have questions or comments, or want to suggest a future topic, email the show at [email protected] ! You can follow Mike Munger on Twitter at @mungowitz