This work presents a theoretical and experimental study of the electrodynamic properties of liposome dispersions. The experiments focus on measuring the electrophoretic mobility and the low-frequency dielectric spectra of unilamellar dioleoylphosphatidylglycerol vesicles suspended in 1-1 and 2-1 electrolytes. The theoretical part presents a relatively simple model for the dynamics of the electric double layer surrounding the liposome. It includes an analytical expression for the frequency-dependent permittivity, which successfully accounts for the experimental spectra. The resulting parameters are consistent with the electrophoretic mobility of the liposome. In the range of electrolyte concentrations investigated, we do observe some effect of the counterion valency, but there is no other ion specificity in the double-layer dynamics.