Bayesian Analysis of Inflation III: Slow Roll Reconstruction Using Model
  Selection
  We implement Slow Roll Reconstruction -- an optimal solution to the inverse
problem for inflationary cosmology -- within ModeCode, a publicly available
solver for the inflationary dynamics. We obtain up-to-date constraints on the
reconstructed inflationary potential, derived from the WMAP 7-year dataset and
South Pole Telescope observations, combined with large scale structure data
derived from SDSS Data Release 7. Using ModeCode in conjunction with the
MultiNest sampler, we compute Bayesian evidence for the reconstructed potential
at each order in the truncated slow roll hierarchy. We find that the data are
well-described by the first two slow roll parameters, \epsilon and \eta, and
that there is no need to include a nontrivial \xi parameter.
