Radiative Corrections and the Palatini Action
  By using the Faddeev-Popov quantization procedure, we demonstrate that the radiative effects computed using the first-order and second-order Einstein-Hilbert action for General Relativity are the same, provided one can discard tadpoles. In addition, we show that the first order form of this action can be used to obtain a set of Feynman rules that involves just two propagating fields and three three-point vertices; using these rules is considerably simpler than employing the infinite number of vertices that occur in the second-order form. We demonstrate this by computing the one-loop, two-point function. 
F. T. Brandt and D. G. C. McKeon
hep-th