The ecological fallacy concerns making conclusions about individuals from aggregates (states).
"An ecological fallacy is a logical fallacy in the interpretation of statistical data where inferences about the nature of individuals are deduced from inference for the group to which those individuals belong.
An example is Red State/ Blue State and income.
Using states, we could conclude that poor states (southern or red states) vote republican.
Yet when run on individuals, rich people vote 60% republican.
The same thing happens in the pharmaceutical industry.
Rather than states, some researchers merely use other researchers published (aggregate) results,
collecting results from many academic pharmaceutical articles (each acting like a state).
Bayer found that they could not reproduce 75% of pharmaceutical academic articles.
When you aggregate (meta-statistics), the knowledgeable complain that you should use individual data, not aggregate data (from articles) to make proper conclusions.
Further examples of the "ecological fallacy" are numerous.
State confounds with another variable, and its extrication can take decades of research, though Bayesian hierarchical models with separate errors at each level can probably extricate the problem these days.
Using aggregate data to make conclusions about individuals has been rejected since the 1950 seminal article by the researcher William S. Robinson. That's 60 years ago! We should become more statistically literate!