demonstrates that the effect is meagre. To further explore the quality of the  and MLE reconstructions and to ascertain that the regularization term does not cause a significant reduction in the amplitude of the bulk flow, we apply  and MLE to the mock data but with true velocities amplified by a factor of 1.5. Everything else, including the regularization term in (\[eq:chi\]), remained the same. The reconstructed $\vace$ and $\vmle$ versus true amplified bulk flow are shown in figure (\[fig:scatt15\]). Both  and MLE perform well even with this amplification of the bulk flow in the mocks.

In both  and MLE, the slopes of the regression lines plotted in (\[fig:scatt\]) are close, but not equal to unity. The deviation from unity is significant (compared to the scatter of the points) and persists when the regression is done using all the 2200 mock points. This small but statistically significant bias depends on the radius of the sphere for which bulk flow is computed. The bias can easily be calibrated using the mock catalogues. Hereafter, all reconstructed bulk flows, from  and MLE, are corrected for the systematic bias in the mean of the estimated bulk given the mean of the true value. In 