In his blog Ideas, Santa Clara University economist David Friedman (yes, he's Milton's son) wrote about the cost of eyeglasses. He was curious why a new frame and set of lenses costs less than $10 online, but five times that amount or more at most stores. Part of the answer lies in statutes like Arizona's §32-1684.01, which states that anyone wanting to open an eyeglass store must "provide evidence to the board's satisfaction that at least one licensed dispensing optician works at the optical establishment on a full-time basis." That means the Arizona State Board of Dispensing Opticians, the licensing...