  We consider two different definitions for loop corrections to the primordial
power spectra. One of these is to simply correct the mode functions in the tree
order relations using the linearized effective field equations. The second
definition involves the spatial Fourier transform of the 2-point correlator.
Although the two definitions agree at tree order, we show that they disagree at
one loop using the Schwinger-Keldysh formalism, so there are at least two
plausible ways of loop correcting the tree order result. We discuss the
advantages and disadvantages of each.
