  Measurements of the cosmic microwave background (CMB) favour models of
inflation with a small tensor-to-scalar ratio r, as predicted by the
Starobinsky R + R^2 model. It has been shown previously that various models
based on no-scale supergravity with different forms of superpotential make
predictions similar to those of the Starobinsky model. In this paper we present
a unified and general treatment of Starobinsky avatars of no-scale
supergravity, using the underlying non-compact SU(2,1)/SU(2) x U(1) symmetry to
demonstrate equivalences between different models, exhibiting 6 specific
equivalence classes.
