  We study the phenomenological constraints on a recently proposed model of
open inflation in the context of induced gravity. The main interest of this
model is the relatively small number of parameters, which may be constrained by
many different types of observation. We evaluate the complete spectrum of
density perturbations, which contains continuum sub-curvature modes, a discrete
super curvature mode, and a mode associated with fluctuations in the bubble
wall. From these, we compute the angular power spectrum of temperature
fluctuations in the microwave background, and derive bounds on the parameters
of the model so that the predicted spectrum is compatible with the observed
anisotropy of the microwave background and with large-scale structure
observations. We analyze the matter era and the approach of the model to
general relativity. The model passes all existing constraints.
