  We propose an extraction of the running coupling constant of QCD in the
infrared region from experimental data on deep inelastic inclusive scattering
at Bjorken x -> 1. We first attempt a perturbative fit of the data that extends
NLO PQCD evolution to large x values and final state invariant mass, W, in the
resonance region. We include both target mass corrections and large x
resummation effects. These effects are of order O(1/Q^2), and they improve the
agreement with the Q^2 dependence of the data. Standard analyses require the
presence of additional power corrections, or dynamical higher twists, to
achieve a fully quantitative fit. Our analysis, however, is regulated by the
value of the strong coupling in the infrared region that enters through large x
resummation effects, and that can suppress, or absorb, higher twist effects.
Large x data therefore indirectly provide a measurement of this quantity that
can be compared to extractions from other observables.

High Energy Physics - Phenomenology