The amount of Goods created or Service provided in an Hour is within a confidence interval for each individual, and as a collection, an global interval that cannot increase without additional capital, training, or experience. However, training and experience does not "grow" in the long run as a new generation of workers is needed. It is only cyclical, where between generations, there exists high training and experience, but when the new generation joins, the old generation retires, then the training and experience is gone and needs to restart.
Productivity by Cost
This measure of Productivity is better for cost or cost-benefit analysis. Paying a worker half as much will double productivity since that will half the denominator without changing the numerator. This type of productivity is important because "Illegal Immigrant" Supporters who wish to neither legalize nor deport Illegal Immigrants so that these "Illegal Immigrant" Supporters may exploit these cheaper labors from the Illegal Immigrants.
Fairness should follow the trend of America. The split of labor is 1/3 to capital and 2/3 to labor. When the split of revenue defers from this ideal level in favor of capital, workers are exploited. When workers feels that they are exploited, they are demotivated from working, so their productivity goes down.