  A comprehensive analysis of the competition between photo-proton and
photo-neutron disintegration yields is undertaken by constraining
photo-absorption data with physics principles -- namely, dipole sum rules,
decay properties to open channels, isospin selection rules and statistical
evaporation from compound nucleus formation. The trend and magnitude of
disintegration yields for self-conjugate nuclei are in agreement with the
evaporation model of Blatt and Weisskopf. A substantial improvement is found
between the exponential trend presented in this work and that determined by
Morinaga using a similar approach. This work allows for the evaluation of
frequently missing or inconsistent photo-proton contributions, which impacts
the photo-disintegration of light and neutron-deficient nuclei, where
photo-proton contributions are relevant.
