Impact of cosmic variance on predictions from the parametric model. Lines show the difference between the best-fitting models to P_3D and P_1D measurements from the CENTRAL and SEED simulations, divided by $\sqrt{2}$ times the best-fitting model to their average. The top panel shows the results for the Lyman-α linear biases (b_δ and b_η), while the middle and bottom panels display the results for P_3D and P_1D at z = 3, respectively. The impact of cosmic variance on model predictions is approximately an order of magnitude smaller than on simulation measurements (see Fig. A.1).