Interesting. In my Disney example above, service has declined quite dramatically overall in the past few years. Many people attribute that in part to the mandatory tips imposed ie that servers are not as motivated to provide decent service, as they know that they will be tipped a minimum of 18% regardless of the service they do provide.

Of course, that is an 'artificial' environment, with a large number of unskilled, poorly paid workers in large part supplemented by exchange program workers and/or college program workers.