Final answer:
Tony's barbershop is considered a nonconforming use or grandfathered property, legal at the time of establishment but not in full compliance with later zoning changes. Long-standing businesses like this relate to urban change and showcase economic principles such as diminishing marginal productivity.
Step-by-step explanation:
Tony works as a barber in a shop that his grandfather built before the area was zoned residential. The barbershop that Tony operates can be best described as a nonconforming use or grandfathered property. This term is used in urban planning and zoning to refer to a property that was legally established according to the zoning regulations in place at the time but does not comply with new zoning rules that were instituted later, such as the residential zoning that occurred 25 years ago in Tony's case. While the barbershop no longer aligns with the current zoning designation, it is allowed to continue operation because it existed prior to the change.
Over time, areas evolve and urban planning concepts can lead to changes in how land is used, as in the case of gentrification, where newer businesses such as hipster coffee shops open up in traditionally less affluent neighborhoods. But long-lasting businesses like Tony's barbershop represent a consistency in the community and offer insight into the history of local commerce and societal norms, such as the separation of gender-specific services in personal grooming. Business operations like Tony's also display economic principles, such as diminishing marginal productivity, when adding more workers leads to decreasing marginal gains and potentially increased operational costs.