  Zero-bin subtractions are required to avoid double counting soft
contributions in collinear loop integrals in Soft-Collinear Effective Theory
(SCET). In traditional approaches to factorization, double counting is avoided
by dividing jet functions by matrix elements of soft Wilson lines. In this
paper, we compare the two approaches to double counting, studying the quark
form factor and deep inelastic scattering (DIS) as x_B \to 1 as examples. We
explain how the zero-bin subtractions in SCET are required to reproduce the
well-established factorization theorem for DIS as x_B \to 1. We study one-loop
virtual contributions to the quark form factor and real gluon emission diagrams
in DIS. The two approaches to double counting are equivalent if dimensional
regularization (DR) is used to regulate infrared (IR) divergences. We discuss
in detail ambiguities in the calculation of one-loop scaleless integrals in DR
in SCET and perturbative QCD. We also demonstrate a nontrivial check of the
equivalence of the zero-bin subtraction and the soft Wilson line subtraction in
the virtual two-loop Abelian contributions to the quark form factor.
