Reverse Causality in Size-Dependent Growth

Oscar Garcia


Size-dependent growth is likely to be growth-dependent size instead. Larger organisms do not necessarily grow faster, but faster-growing ones always tend to be larger. This fact has been generally ignored. Correct causality structures are essential for plausible predictions outside the range of the data. Some techniques potentially useful for studying these issues are brie y described. In forestry, the relevance of multiple size measures like volume, height, diameter and basal area greatly complicates the picture. Additionally, purely mathematical sources of growth-size correlations arise. Physiological considerations suggest avoiding stem thickness measures as explanatory variables in growth equations.


Confounding, bias, consistency, path analysis, structural equation modelling, mixed eects, endogenous variables, instrumental variables, allometry.

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