  We consider five-dimensional supergravity theories with eight or sixteen
supercharges with Abelian vector fields and ungauged scalars. We address the
question under which conditions these theories can be interpreted as effective
low energy descriptions of circle reductions of anomaly free six-dimensional
theories with (1,0) or (2,0) supersymmetry. We argue that classical and
one-loop gauge- and gravitational Chern-Simons terms are instrumental for this
question.
