Strengthening a Claim about Minimum Wage and Productivity

In a recent public debate, a politician claimed that increasing the minimum wage would lead to higher overall employee productivity. Supporting this claim, the politician cited a study showing that companies with higher minimum wages tend to report lower employee turnover rates. However, some critics argue that while lower turnover can lead to cost savings, it does not necessarily correlate with increased productivity.

The politician's logic can be criticized by the fact that it overlooks other factors that might contribute to productivity, such as workplace environment and training. To strengthen the politician's argument, which of the following statements would be the most helpful to include?