The ecological fallacy: How to spot one and tips on how to use one to your advantage

Hume Winzar
  • Australasian Marketing Journal (AMJ), February 2015, Elsevier
  • DOI: 10.1016/j.ausmj.2014.12.002

It's a mistake to think that the average of a group applies to individuals in the group

Photo by Leo Foureaux on Unsplash

Photo by Leo Foureaux on Unsplash

What is it about?

The ecological fallacy is a common and little understood error in the interpretation of statistical data wherein inferences about individuals are based on the aggregate of the group from which they belong. This opinion piece overviews the importance of avoiding the error and illustrates the ease with which mistakes in inference can be made by examining some papers appearing in recent conferences and journals, and by demonstrating with artificial data representing Hofstede’s cultural dimensions. It concludes with an appeal for caution when considering the combination of aggregate data with our surveys of individuals.

Why is it important?

Business decisions, government policy and often even our personal interactions are affected by what we believe is typical of a group. What is "typical" often is reduced to the simple average of the group. That simplification ignores the range of values within the group.


Associate Professor Hume F Winzar
Macquarie University

I've been pleasantly surprised at the positive feedback on this paper, and saddened that some high-level authors continue to make the error. (although as a reviewer I've been able to point authors to an entertaining critique of their work.)

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The following have contributed to this page: Associate Professor Hume F Winzar