it also depends on the industry. a lot of these same arguments apply to corporate taxation, and are really tied to how mobile the business is.

a call centre can get up and move fairly easily. a mcdonald's isn't going anywhere if it's successful, but the burger king across the street might in fact shut down. a mine or a forest is tied to the geography and couldn't move regardless of consequences. & etc

also, you'd expect low unemployment to have a causal effect on increasing wages.