Data Envelopment Analysis (DEA) evaluates the relative efficiency of d
ecision-making units (DMUs) but does not allow for a ranking of the ef
ficient unit's themselves. A modified version of DEA based upon compar
ison of efficient DMUs relative to a reference technology spanned by a
ll other units is developed. The procedure provides a framework for ra
nking efficient units and facilitates comparison with rankings based o
n parametric methods.