Recent experiments and simulations show that large chaotropic anions favor solvation at the water surface.. mainly due to induction interactions dominated by ionic polarizabilities. We compare the solvation free-energy components of iodide at the water surface and bulk with a recent, polarizable force field. The bulk position is stabilized by the interaction between the iodide permanent charge and the solvent permanent dipole moments; the surface is favored by the iodide polarizability and the reduced cavity accommodating the solute. The ionic solvation is not described satisfactorily by linear response; the non-linearity of the iodide induced dipole moment is discussed. (c) 2005 Elsevier B.V. All rights reserved.