Degeneracies between RSD parameters β, σ_v, effective bias and the power spectrum at k = 0.4h Mpc^-1. The shaded regions mark the 68% and 95% confidence intervals from VIPERS chain and the star symbols mark the mean value. The points give the distribution of mean values derived from mock catalogues. The histograms along the diagonal give the marginalised distributions of each parameter chain. The filled histogram gives the distribution from the VIPERS chain, while the solid line is the distribution of mean values derived from the mock catalogues.