It's not technically hereditary. But if the job licenses are a finite resource, and the licensee "owns" the license and is allowed to give/sell it to a person of their choice, and the job is reasonably pleasant/profitable... they're very likely to pass it on to their children, unless those children have other plans.
Pharmacies in Italy work much like notaries, although they obviously provide a much more useful service. My understanding is that in part of the US taxis work the same way, with limited # of "medallions" being treated as an investment.
