  Large-Momentum Effective Theory (or LaMET) advocated by the present authors
provides a direct approach to simulate parton physics in Eulidean lattice QCD
theory. Recently, there has been much interest in this theory in the
literature, with some questioning its validity and effectiveness. Here we
provide some discussions aiming at a further exposition of this approach. In
particular, we explain why it does not have the usual power divergence problem
in lattice QCD calculations for the moments of parton distributions. We show
that although the Ioffe-time distribution provides an alternative way to
extract the parton distribution from the same lattice observable, it also
requires the same large momentum limit as in LaMET to obtain a precision
calculation. With a proper quantification of errors, both extraction methods
should be compared with the same lattice data.
