# Are slacks the same as mix-inefficiency?

On the diagram below it is stated that A' has input slacks as it could reduce the amount of $x_2$ and still be on the frontier (by moving to C). However I recall mix-inefficiency having a similar definition. Is there any difference between slacks and mix-inefficiency?

• Mix-inefficiency may include cases of slack, but may include other situations too – Henry Jul 3 '18 at 23:52