Understanding the "Ecological Fallacy" in Statistics/Logic From what I understand, an ecological fallacy is the failure in reason when you make an inference about an individual based upon aggregate data of the group from which the individual belongs. 
Assuming the definition above...
Suppose I am an all powerful God and know that in the set of all automobile drivers in the world, there exists a subset that break the speed limit every day and 99% of those speedsters are male. 
Now, let's say I conduct the experiment of randomly choosing one person out of the set of all speedsters.  Can I infer that the person will "PROBABLY" be male?  I am being told I can't because this is an ecological fallacy.   I am inferring something about the individual from the group data, but I'm having a hard time understanding why this is a failure in reasoning.
I did not infer that they "Will BE" male.  I simply inferred that they will "PROBABLY" be male.  There is a difference.
I think it would be a safe bet to conclude that the speedsters chosen were probably male.  This seems obvious to me based up on the following simple fact... If I were to repeatedly conduct the experiment of selecting speedsters... in the long run 99% of the time those selected would be men.  Seems like a good bet to take in Vegas.


*

*Am I committing an ecological fallacy here?  Why are why not? 

*If I am, where is the failure in reason?  

*Is my definition for Ecological Fallacy at the top correct?  If not, can you give me clear and concise definition or exact requirements that would allow me to classify any inference made as an "ecological fallacy"? 
 A: The predictive reasoning you are describing is not fallacious, and is not the kind of reasoning that the ecological fallacy is concerned with.  As a general principle, if you have data that show some statistical relationship between the characteristics of people, it is legitimate to use one characteristic as a predictor of the other.  Hence, it is massively overbroad to say that you cannot legitimately make inferences about individuals from knowledge of group characteristics.
What the ecological fallacy is concerned with is cases where statistical associations of aggregates of characteristics over groups differ from the underlying statistical associations of the corresponding individual characteristics (e.g., cases like Simpson's paradox).  The example often cited to illustrate this is in the original work of Robinson (1950), where the author presents an example using data on literacy and immigrant percentages in the United States.  Analysing the data over nine census regions, he observed that regions with higher percentages of immigrants tended to have higher literacy rates.  The "ecological fallacy" in this case would occur if you allowed this statistical result to lead you to (wrongly) conclude that immigrants have higher literacy rates than non-immigrants.  In fact, Robinson observed that data at the individual level confirm that immigrants have lower levels of literacy than non-immigrants.  The reason for this apparent incongruity is that immigrants tend to settle in places that have high literacy rates among the non-immigrants.
Robinson explains the relationship between correlations of characteristics in aggregates and correlations of those same characteristics in individuals depends largely on within-group variation.  His explanation is as follows:

The relation between ecological and individual correlations ...
  provides a definite answer as to whether ecological correlations
  [i.e., correlations of characteristics in aggregates] can validly be
  used as substitutes for individual correlations.  They cannot.  While
  it is theoretically possible for the two to be equal, the conditions
  under which this can happen are far removed from those ordinarily
  encountered in data.  From a practical standpoint, therefore, the
  only reasonable assumption is that an ecological correlation is almost
  certainly not equal to its corresponding individual correlation. 
  (p. 352)


Robinson, W. S. (1950) Ecological Correlations and the Behavior of Individuals. American Sociological Review 15(3), pp. 351–357.
