  The joint analysis of clustering and stacked gravitational lensing of galaxy
clusters in large surveys can constrain the formation and evolution of
structures and the cosmological parameters. On scales outside a few virial
radii, the halo bias, $b$, is linear and the lensing signal is dominated by the
correlated distribution of matter around galaxy clusters. We discuss a method
to measure the power spectrum amplitude $\sigma_8$ and $b$ based on a minimal
modelling. We considered a sample of $\sim 120000$ clusters photometrically
selected from the Sloan Digital Sky Survey in the redshift range $0.1<z<0.6$.
The auto-correlation was studied through the two-point function of a subsample
of $\sim 70000$ clusters; the matter-halo correlation was derived from the weak
lensing signal of the subsample of $\sim 1200$ clusters with
Canada-France-Hawaii Lensing Survey data. We obtained a direct measurement of
$b$, which increases with mass in agreement with predictions of the
$\Lambda$CDM paradigm. Assuming $\Omega_\mathrm{M}=0.3$, we found
$\sigma_8=0.78\pm0.16$. We used the same clusters for measuring both lensing
and clustering and the estimate of $\sigma_8$ did require neither the
mass-richness relation, nor the knowledge of the selection function, nor the
modelling of $b$. With an additional theoretical prior on the bias, we obtained
$\sigma_8=0.75\pm0.08$.
