Which effect usually favors, dominates and is a deciding factor for the stability of conjugated carbonyls

The mesomeric effect involves the delocalization of the  electrons in a conjugated orbital system. Inductive effect is an effect regarding the transmission of unequal sharing of the bonding electron through a chain of atoms in a molecule, leading to a permanent dipole in a bond. Resonance on the other hand is involved in dispersion of charge up to any distance of carbon and stabilize the charge