excess {Benchmarking} | R Documentation |
Excess input compared over frontier input and/or less output than frontier/transformation/optimal output.
excess(object, X = NULL, Y = NULL)
object |
A Farrell object as returned from functions like dea, dea.direct, linksdea, and mea. |
X |
Input matrix, only neccesary for ordinary input Farrell efficiency |
Y |
Ouput matrix , only neccesary for ordinary output Farrell efficiency |
For Farrell input efficiency E the exess input is (1-E) X and for Farrell ouput efficiency F the missing output is (F-1) Y.
Notice that the excess calculated does not include any slackvalues. In
case slacks are present and calculated it might be more appropriate
to add slack; i.e. to use excess(object, X, Y) + slack(X, Y, object)
.
For directional efficiency e in the direction D the excess input is e D.
If a firm is outside the technology set, as could be the case when calculating super-efficiencies, the Farrell input efficiency is larger then 1 and then the excess values are negative.
Return a matrix with exces input and/or less output.
Peter Bogeroft and Lars Otto larsot23@gmail.com
Peter Bogetoft and Lars Otto; Benchmarking with DEA, SFA, and R; Springer 2011
x <- matrix(c(100,200,300,500,100,200,600),ncol=1) y <- matrix(c(75,100,300,400,25,50,400),ncol=1) e <- dea(x,y) excess(e,x) x - eff(e) * x e <- dea(x,y, ORIENTATION="graph") excess(e, x, y) x - eff(e) * x 1/eff(e) * y -y me <- mea(x,y) excess(me)