  We discuss the methodology of quantum Monte Carlo calculations of the
effective mass based on the static self energy, $\Sigma(k,0)$. We then use
variational Monte Carlo calculations of $\Sigma(k,0)$ of the homogeneous
electron gas at various densities to obtain results very close to perturbative
$G_0 W_0$ calculations for values of the density parameter $1 \le r_s \le 10$.
The obtained values for the effective mass are close to diagrammatic Monte
Carlo results and disagree with previous quantum Monte Carlo calculations based
on a heuristic mapping of excitation energies to those of an ideal gas.
