  We study hierarchical network models which have recently been introduced to
approximate the Chalker-Coddington model for the integer quantum Hall effect
(A.G. Galstyan and M.E. Raikh, PRB 56 1422 (1997); Arovas et al., PRB 56, 4751
(1997)). The hierarchical structure is due to a recursive method starting from
a finite elementary cell. The localization-delocalization transition occurring
in these models is displayed in the flow of the conductance distribution under
increasing system size. We numerically determine this flow, calculate the
critical conductance distribution, the critical exponent of the localization
length, and the multifractal exponents of critical eigenstates.
