  We present a direct comparison of the clustering properties of two redshift
surveys covering a common volume of space: the recently completed IRAS Point
Source Catalogue redshift survey (PSCz) containing 14500 galaxies with a
limiting flux of 0.6 Jy at 60 microns, and the optical Stromlo-APM survey
containing 1787 galaxies in a region of 4300 deg^2 in the southern Galactic
cap. We use three methods to compare the clustering properties: the
counts-in-cells comparison of Efstathiou (1995), the two-point cross
correlation function, and the Tegmark (1998) `null-buster' test. We find that
the Stromlo variances are systematically higher than those of PSCz, as expected
due to the deficit of early-type galaxies in IRAS samples. However we find that
the differences between the cell counts are consistent with a linear bias
between the two surveys, with a relative bias parameter b_rel =
b_Stromlo/b_PSCz \approx 1.3 which appears approximately scale-independent. The
correlation coefficient R between optical and IRAS densities on scales \sim 20
Mpc/h is R > 0.72 at 95% c.l., placing limits on types of `stochastic bias'
which affect optical and IRAS galaxies differently.
