We analyze two scattering mechanisms that might cause intrinsic electronic
resistivity in multi-wall carbon nanotubes: scattering by dopant impurities,
and scattering by inter-tube electron-electron interaction. We find that for
typically doped multi-wall tubes backward scattering at dopants is by far the
dominating effect.Comment: 6 pages, 2 figures, to appear in Phys. Rev.