We describe a simple lattice model of higher-curvature quantum gravity in two
dimensions and study the phase structure of the theory as a function of the
curvature coupling. It is shown that the ensemble of flat graphs is
entropically unstable to the formation of baby universes. In these simplified
models the growth in graphs exhibits a branched polymer behaviour in the phase
directly before the flattening transition.Comment: 18 pages LaTeX, 3 .eps figures, uses epsf.tex; clarifying comments
added and typos correcte