  We examine the spatial clustering of extremely red objects (EROs) found in a
relatively large survey of 700 arcmin^2, containing 400 galaxies with R-Ks>5 to
Ks=19.2. A comoving correlation length r_0=12\pm3 /h Mpc is derived, under the
assumption that the selection function is described by a passively evolving
early-type galaxy population, with an effective redshift of z~1.2. This
correlation length is very similar to that of local L* elliptical galaxies
implying, at face value, no significant clustering evolution in comoving
coordinates of early-type galaxies to the limiting depth of our sample, z~1.5.
A rapidly evolving clustering bias can be designed to reproduce a null result;
however, our data do not show the corresponding strong reduction in the average
population density expected for consistency with underlying growth of the
mass-function. We discuss our data in the context of recent ideas regarding
bias evolution. The uncertainty we quote on r_0 accounts for the spikey
redshift distribution expected along relatively narrow sightlines, which we
quantify with detailed simulations. This is an improvement over the standard
use of Limber's equation which, because of its implicit assumption of a smooth
selection function, underestimates the true noise by a factor of ~ 3 for the
parameters of our survey. We propose a general recipe for the analysis of
angular clustering, suggesting that any measurement of the angular clustering
amplitude, A, has an intrinsic additional uncertainty of \sigma_A/A=\sqrt{AC},
where AC is the appropriate integral constraint.
