Why did Mr. Schmitt never keep a clerk long in The Egypt Game?
Mr. Schmitt never keeps a clerk very long because "he (pays) such low salaries". Because of this, it takes a long time to get waited on at Schmitt's Variety Store, especially if you are a kid - "Mr. Schmitt, himself, never wait(s) on kids until after all the grown-ups (are) taken care of, no matter who'd been there longest". When the Egypt gang goes to Schmitt's to get some pens, it takes most of the afternoon for them to get their purchase. On that particular day, Mr. Schmitt is the only one working, and the kids wait and wait just about forever for someone to attend to them; it is a very frustrating experience (Chapter 14 - "Hieroglyphics").
Mr. Schmitt's business practices are not always on the up and up in other ways as well. When a young girl is apparently abducted from the neighborhood, he is one of the instigators of a smear campaign to cast suspicion on the Professor. Mr. Schmitt organizes a "not-so-secret campaign to get people to write letters and sign petitions inviting the Professor to leave the neighborhood". Interestingly, the fact that the Professor's shop is a competitor to Schmitt's Variety Store, selling "old and cheap some of the things that Mr. Schmitt (sells) new and expensive", is conveniently overlooked by both Mr. Schmitt and the people who support the petition (Chapter 8 - "Prisoners of Fear").