  Deep inelastic scattering at small x can be described very effectively using
saturation inspired dipole models. We investigate whether such models are
compatible with the numerical solutions of the Balitsky-Kovchegov (BK) equation
which is expected to describe the nonlinear evolution in x of the dipole cross
section. We find that the BK equation yields results that are qualitatively
different from those of phenomenological studies. Geometric scaling is
recovered only towards asymptotic rapidities. In this limit the value of the
anomalous dimension gamma(r,x) at the saturation scale approaches approximately
0.44, in contrast to the value 0.63 commonly used in the models.
