  We investigate theoretically the feasibility of an experimental test of the
Bell-type inequality derived by Mermin for correlated spins larger than 1/2.
Using the Schwinger representation, we link the output fields of two two-mode
squeezers in order to create correlated effective spins between two observers.
Spin measurements will be performed by photon-number-resolved photodetection,
which has recently come of age. We examine the effect of nonideal detection
quantum efficiency---and any other optical loss---on the violation margin of
Mermin's inequality. We find that experimental violation is well accessible for
spins larger than 1 for quantum efficiencies compatible with the current state
of the art.
