Final answer:
We should indeed be concerned about a high degree of correlation when estimating the impact of a training program on 1998 earnings because correlation does not equate to causation and could confound the ability to isolate the program's specific effects.
Step-by-step explanation:
The student asks if there should be concern about the correlation affecting the ability to estimate the impact of a training program on 1998 earnings. The basis of the student's question is that a correlation has been identified, and there is concern about the implications of this on evaluating the effectiveness of a training program.
Using the provided references, it is evident that the Bureau of Labor Statistics data from May 2012 has shown a positive correlation between earnings and education, suggesting that as education and training levels increase, unemployment rates decrease. However, a positive correlation alone does not establish causation; it simply indicates that two variables move in the same direction. Therefore, if the correlation in question is quite high, it may affect the ability to isolate the impact of the training program on earnings separate from other factors. Causation is more complex to establish and requires ruling out other variables that might affect the outcome — a process which is confounded if there are multiple interventions (such as software use and exercise in the reference).