# “Elasticity of marginal utility of consumption ( μ ) with respect to utility.” (Green Book quote)?

In the Green Book (page 97) it is stated "the elasticity of marginal utility of consumption (μ) with respect to utility".

What is it? Is it an error ? I always heard of the elasticity of the marginal utility with respect to consumption...

• It is just an unnecessary (and apparently confusing) wording, that probably emerged because the author had already used the word "consumption" while he "remembered" that the concept description should end with a "with respect to..." It is the measure we all know, in any case, nothing fancy. – Alecos Papadopoulos Jan 2 '17 at 18:42

Mere googling leads me to find a bunch of references about elasticity of marginal utility.

Here Professor Acemoglu defines the elasticity of marginal utility as the inverse of the intertemporal elasticity of substitution (pagg. 17-18).

Here you can find a question analogous to yours together with an answer explained in an easier way than Acemoglu's lecture.

If you are interested in something more empirical, have a look here: it is a paper by David Evans about the empirical estimation of elasticity of marginal utility in OECD countries.