Cost disease of personal services

In certain sectors, notably the performing arts, productivity (in terms of output per person per hour) necessarily does not change over the centuries. If those employed in such sectors are to have anything like a contemporary standard of living, the relative cost of their services will be much greater than it was in centuries past. If a particular service is deemed indispensable, the relative cost of that service will continue to rise to keep pace with the dramatic improvements in productivity in other sectors.