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Ecological Study Design

Environmental Health

  1. Lianne Sheppard

Published Online: 15 SEP 2006

DOI: 10.1002/9780470057339.vae007

Encyclopedia of Environmetrics

Encyclopedia of Environmetrics

How to Cite

Sheppard, L. 2006. Ecological Study Design. Encyclopedia of Environmetrics. 2.

Author Information

  1. University of Washington, WA, USA

Publication History

  1. Published Online: 15 SEP 2006


The purposes of ecological studies range from descriptive (e.g. hypothesis-generating) to inferential. The target of inference may be the group (called ecological inference) or the individual (called biological inference). Ecological studies are most appropriate for assessing the effects of interventions on populations, although the inference can be limited relative to an individual-level study. Their applicability to etiological hypotheses about individuals is much more controversial, due to the risk of committing the ecological fallacy. This fallacy is present when characteristics of individuals are wrongly inferred from grouped data. Although these reservations have a sound basis, most ecological study literature does not distinguish between issues inherent to the analysis of opportunistic observational data, and those pertinent to valid biological inference from group-level analyses.


  • ecological inference;
  • biological inference;
  • ecological fallacy;
  • aggregate data;
  • environmental exposure;
  • health effect;
  • multilevel study;
  • contextual effects