Results may be correlated with effort if you consider a single person. However, in real life, you're usually competing with someone else.
Let's say we're comparing two employees: X works hard 80 hours a week; Y works only 40 hours a week and takes long lunches. But somehow, Y still ends up producing more results of a better quality. A rational manager should pay Y more than X, since it's only the end results that are of value to the company.
Let's say we're comparing two employees: X works hard 80 hours a week; Y works only 40 hours a week and takes long lunches. But somehow, Y still ends up producing more results of a better quality. A rational manager should pay Y more than X, since it's only the end results that are of value to the company.