Energy efficiency measurement is crucial when planning energy reduction policies.
However, decision makers understandably will be reluctant to act in the absence of solid data
and results supporting a policy position. The main objective of this paper is to propose an
alternative method to measure farm energy efficiency. This method is based on the Data
Envelopment Analysis (DEA) approach in a cost framework introduced by Farrell (1957) and
developed by Färe et al. (1985). We decompose the energy efficiency measurement into two
components, namely technical and allocative efficiencies. Here, input prices are replaced by
their energy content. The energy efficiency model is used to explore the optimal input-mix
that produces the current outputs at minimum energy-consumption. We show that this
decomposition can help policy makers considerably to design accurate energy policies. The
presence of uncertainty on data, and more particularly on energy content of inputs, leads us to
recommend exploiting the methodologies proposed for calculating the bounds of efficiency
measurement in order to produce more robust results. We expect to alert policy-makers in the
fact that efficiency is not a fixed value and should be considered with caution. A 2007
database of French farms specialized in crops is used for empirical illustration
