In two recent papers , we developed a powerful technique to link the distribution of galaxies to that of dark matter haloes by considering halo occupation numbers as function of galaxy luminosity and type .
In this paper we use these distribution functions to populate dark matter haloes in high-resolution N -body simulations of the standard \Lambda CDM cosmogony with \Omega _ { m } = 0.3 , \Omega _ { \Lambda } = 0.7 , and \sigma _ { 8 } = 0.9 .
Stacking simulation boxes of 100 h ^ { -1 } \ > { Mpc } and 300 h ^ { -1 } \ > { Mpc } with 512 ^ { 3 } 
particles each we construct Mock Galaxy Redshift Surveys out to a redshift of z = 0.2 with a numerical resolution that guarantees completeness down to 0.01 L ^ { * } .
We use these mock surveys to investigate various clustering statistics .
The predicted two-dimensional correlation function \xi ( r _ { p } , \pi ) reveals clear signatures of redshift space distortions .
The projected correlation functions for galaxies with different luminosities and types , derived from \xi ( r _ { p } , \pi ) , match the observations well on scales larger than \sim 3 \ > h ^ { -1 } { Mpc } .
On smaller scales , however , the model overpredicts the clustering power by about a factor two .
Modeling the “ finger-of-God ” effect on small scales reveals that the standard \Lambda CDM model predicts pairwise velocity dispersions ( PVD ) that are \sim 400 \ > { km } { s } ^ { -1 } too high at projected pair separations of \sim 1 h ^ { -1 } \ > { Mpc } .
A strong velocity bias in massive haloes , with b _ { vel } \equiv \sigma _ { gal } / \sigma _ { dm } \sim 0.6 ( where \sigma _ { gal } and \sigma _ { dm } are the velocity dispersions of galaxies and dark matter particles , respectively ) can reduce the predicted PVD to the observed level , but does not help to resolve the over-prediction of clustering power on small scales .
Consistent results can be obtained within the standard \Lambda CDM model only when the average mass-to-light ratio of clusters is of the order of 1000 \ > ( { M } / { L } ) _ { \odot } in the B -band .
Alternatively , as we show by a simple approximation , a \Lambda CDM model with \sigma _ { 8 } \simeq 0.75 may also reproduce the observational results .
We discuss our results in light of the recent WMAP results and the constraints on \sigma _ { 8 } 
obtained independently from other observations .