  High-temperature superconducting cuprates are distinguished by an enigmatic
pseudogap which opens near optimal doping where the superconducting transition
temperature is highest. Key questions concern its origin and whether it is
essential in any way to superconductivity. Recent field-induced normal-state
transport experiments on hole-doped cuprates have measured abrupt changes in
the doping dependent Hall number and resistivity, consistent with a drop in
carrier density from $1+p$ to $p$ holes per copper atom, on entering the
pseudogap phase. In this work the change in resistivity is analyzed in terms of
an antiferromagnetic-order-induced Fermi surface reconstruction model that has
already successfully described the Hall number. In order for this model to
describe the resistivity we find that the zero-temperature mean free path must
also drop abruptly in proportion to the size of the Fermi surface. This
suggests that intrapocket scattering underlies the observed upturn in
resistivity in the pseudogap state.
