  We study the electronic structure of the ladder compounds (SrCa)CuO 14-24-41
and SrCuO 123. LDA calculations for both give similar Cu 3d-bands near the
Fermi energy. The hopping parameters estimated by fitting LDA energy bands show
a strong anisotropy between the t_perp t_par intra-ladder hopping and small
inter-ladder hopping. A downfolding method shows that this anisotropy arises
from the ladder structure.The conductivity perpendicular to the ladders is
computed assuming incoherent tunneling giving a value close to experiment.
